Aerospace titanium castings
2014年5月20日星期二
Aerospace titanium castings Breasts is regarded as the most notable female secondary
Breasts is regarded as the most notable female secondary sex characteristics . It is said that the habit of Oriental women bra Bra from Yang invention. Social progress , changing times ,Titanium alloy valve always had the habit of bra Oriental women have begun to wear sun dress , low-cut dress and other clothing , and some also use a variety of beautiful bra to beautify the shape of the breast .
In addition to the size of the female breast affected by hormones , but also by a variety of genetic factors , environmental factors, nutrition , weight , physical exercise. Some people in order to make up the breasts while taking hormone drugs , endocrine disorders will inevitably bring , the beauty of women must be careful to use. Breast is it has the potential to cause harm to breast tissue under the negative influence . It is understood that the U.S. Food and Drug Administration (FDA) prohibited such products to market. Some foreign countries have silicon breast augmentation capsules bags in vivo safety questioned .
Experts recommend physical exercise plus choose the ideal bra is the most appropriate. Bra has recently Titanium precision castings introduced a new foreign high-tech , with its bottom rim "shape memory alloy" in place of nickel-titanium alloy when heated to a certain temperature , i.e., a predetermined shape to reply , and it is more flexible than the existing rims even after washing distorted , just wore that tie with the temperature curve , the elastic than normal rims doubled in size, will not be deformed . With the popularization and application of titanium , I believe that soon the natural beauty of oriental women will benefit from them.
Jewelry made of titanium , titanium system bra will make wonderful woman in the world . Advantage of titanium is " titanium " Light : titanium, stainless steel accounts for about half of cobalt, chromium and other alloys , it is much lighter than gold 16.3 , in making earrings, necklaces and other jewelry when obvious advantages ;
"Titanium " has good corrosion resistance : it embodies the advantages of jewelry is non-corrosive , not color, can long maintain a good luster, and is not afraid of water ;
"Titanium " has good biocompatibility : good corrosion resistance characteristics of titanium and people make it after long-term exposure does not affect its nature , does not cause allergies. Now in the medical field has been widely used. Therefore, people who are allergic to metal can boldly wear titanium jewelry ;
"Titanium " Can coloring : titanium metal has a very interesting feature , titanium placed on certain current through the electrolyte , the surface will be based on the electrolytic oxide film , and the thickness of the oxide film may decide to change the color while and no external element. Now do the colors are gold , black, blue , brown , titanium casting factory flowers and other colors . This feature makes it more colorful jewelry design , more fashionable ;
High titanium hardness, not easy to deformation , unlike ordinary wear gold and silver jewelry and other period of time need to re- shaping.
Since the material properties of titanium and unique cultural connotation , she will become after the precious metals platinum, gold jewelry is another stylish and classic metal ! Recent years, the Western countries and Japan, South Korea , titanium jewelry industry is booming , and ascendant, titanium jewelry has become a fashion, classic , conservation , personality, health synonymous ! believe that in the near future , Xiuwaihuizhong , sunny temperament of women will add in the next Jin let panacea "Titanium " charm !
2014年5月12日星期一
Aerospace titanium castings From the viewpoint of heat transfer efficiency
Titanium tube heat transfer efficiency to beat rivals
From the viewpoint of heat transfer efficiency, we find that the titanium alloy pipes with other
tubing (e.g., copper-nickel alloy) Aerospace titanium castings match. High strength titanium and high impact resistance allowable
turbidity of seawater with high flow rates and titanium alloys have a high temperature corrosion
resistance, titanium-nickel alloy than copper heat exchanger 60 a weight reduction of 70%, the their
overall heat transfer efficiency is roughly the same.
Due to the longer life of the titanium tube structure to offset one-time investment, in terms of
economic efficiency is also something else. And because of the speed for the entire period in the life
of the tube can reduce downtime, titanium alloy pump thus also receive an additional character. With the growth and
expansion of the use of titanium production, the cost and availability of titanium improved. Titanium
also with 317L stainless steel, Monel alloy 400 and Hastelloy C-276 to compete. It is predicted that
in the middle with seawater cooled heat exchangers, finned whole rolled titanium tube will completely replace copper-based alloy tube.
From the viewpoint of heat transfer efficiency, we find that the titanium alloy pipes with other
tubing (e.g., copper-nickel alloy) Aerospace titanium castings match. High strength titanium and high impact resistance allowable
turbidity of seawater with high flow rates and titanium alloys have a high temperature corrosion
resistance, titanium-nickel alloy than copper heat exchanger 60 a weight reduction of 70%, the their
overall heat transfer efficiency is roughly the same.
Due to the longer life of the titanium tube structure to offset one-time investment, in terms of
economic efficiency is also something else. And because of the speed for the entire period in the life
of the tube can reduce downtime, titanium alloy pump thus also receive an additional character. With the growth and
expansion of the use of titanium production, the cost and availability of titanium improved. Titanium
also with 317L stainless steel, Monel alloy 400 and Hastelloy C-276 to compete. It is predicted that
in the middle with seawater cooled heat exchangers, finned whole rolled titanium tube will completely replace copper-based alloy tube.
2014年4月16日星期三
Aerospace titanium castings Notice on Strengthening the Administration
Notice on Strengthening the Administration of Import of titanium production operations to rectify the order of
State Economic and Trade Commission, Ministry of Foreign Trade and Economic Cooperation State Aerospace titanium castings Environmental Protection Administration of Customs State Administration for Industry and State Administration of Quality and Technical Supervision, State Administration for Entry
State Economic and Trade Commission of Foreign Trade and Economic
Cooperation of the State Environmental Protection Administration of Customs
State Administration for Industry and State Administration of Quality Technology
Exit Inspection and Quarantine Bureau of Supervision
Notice on Strengthening the Administration of Import of titanium production operations to rectify the order of
SETC Trade [ 1999 ] No. 1164
Provinces, autonomous regions, municipalities , separately listed cities and Xinjiang Production and Construction Corps (economic commissions , Economic Commission ) , Office of Foreign Trade ( Commission, Council ) , Guangdong Customs , directly under the Customs , the Environmental Protection Agency , Administration for Industry quality and Technical Supervision , Inspection and Quarantine Bureau directly under the immigration :
As a new high-performance titanium rare quality , cutting-edge technology is indispensable for defense and critical and supportive materials. Since the founding of the great support in the country , China's titanium industry developed rapidly , becoming one of the few countries in the world capable of producing titanium , product quality has reached the international advanced level , especially aviation titanium alloy material , a world leader , enjoys a certain reputation in the international arena . But in recent years , a number of companies and individuals in driving local interests, a large number of illegal import of scrap titanium through border trade and smuggling and other forms , resulting in domestic sunrui Titanium alloy valve production, circulation disorder, seriously affect the normal development of China's titanium industry . To promote the healthy development of domestic titanium industry , to ensure the normal operation of domestic titanium producers , according to the relevant laws and regulations of the country , decided to strengthen the management and consolidation of imported titanium titanium production , operation order . Relevant issues are hereby notified as follows:
First, strengthen titanium import management
( A ) the titanium , titanium alloy , titanium alloy shredded scrap ( specific heading annex ) as the focus of sensitive goods imports , increase customs inspection efforts. Meanwhile, the focus of the trial price of titanium products as customs , the customs at trial must be strictly in accordance with relevant provisions of trial , to prevent price frauds .
In Xinjiang , Inner Mongolia, Heilongjiang various ports , the investigation focused on the implementation of regulatory control , and resolutely crack down by pseudo- reported imports of titanium and other ways of concealing illegal behavior.
Intensify efforts to combat smuggling of titanium , titanium imports of violations and smuggling cases , and resolutely punished according to law .
( B) the strict implementation of the National Environmental Protection Agency , the Ministry of Foreign Trade and Economic Cooperation , Customs, State Administration for Industry and Commerce , the State Administration of 1996 jointly issued "on the promulgation < Provisional Regulations on Administration of Environmental Protection Waste Import " notice " ( environmental Control [ 1996 ] No. 204 ) of the relevant provisions prohibited titanium scrap , scrap titanium alloy , titanium alloy scrap imports, the state environmental protection department shall not issue " waste import approval certificate ." Right to scrap iron and steel, electrical appliances and other scrap metal imports in nominal imports of titanium or entrained units and individuals , once discovered , in accordance with the relevant provisions of the punishment.
Import and export operation rights and have the right to operate cross-border trade enterprises are not allowed to import or import agent titanium scrap , scrap titanium alloy , titanium alloy scrap , once discovered , is handled by the foreign trade department according to relevant regulations , the circumstances are serious business , cancel or suspend its right to operate import and export business.
( 3) to titanium , titanium alloy product catalog to include statutory inspection by the State Administration for Entry for the implementation of the statutory inspection of imported titanium , do not ban the import of compliant products .
Second, to strengthen titanium processing production management
Enterprises for the production of titanium production license system , the quality and technical supervision departments providers nonferrous metals industry management department of the existing producers of titanium titanium production licenses issued . Unlicensed businesses and individuals are not allowed to production and processing of titanium and its products .
Quality and technical supervision departments in conjunction with the non-ferrous metal industry management departments to strengthen the production and processing of titanium product quality supervision and inspection , who found adulterated, or impurities, shoddy, substandard goods as well as qualified products use imported scrap titanium titanium raw materials , according to the relevant regulations of the State to punish .
Third, rectify market order flow titanium
State sales and acquisitions of titanium metal titanium , titanium alloy , titanium alloy scrap ( including unwrought titanium , powder , profiles , etc. ) of a unified management . Titanium ventures have been set up after the State Economic and Trade Commission or its authorized approval, prior to June 1, 2000 to the industrial and commercial administrative authorities for re-registration . The new application for the establishment of titanium enterprises approved by the State Economic and Trade Commission or its authorized units , the industry and commerce administration authorities for registration . Without the approval and registration of , any enterprise or individual shall engage in business activities titanium .
Recently, the State aerospace investment castings Administration for Industry and Commerce in conjunction with the quality and technical supervision departments of Baoji , Shenyang two centralized straighten titanium market , strictly regulate the processing and marketing behavior of titanium products , strengthen quality supervision of related products.
All relevant departments should actively cooperate , to work together to strengthen titanium import management and good rectification work on titanium production, operation order.
From the date of the notice issued by the Executive .
State Economic and Trade Commission, Ministry of Foreign Trade and Economic Cooperation State Aerospace titanium castings Environmental Protection Administration of Customs State Administration for Industry and State Administration of Quality and Technical Supervision, State Administration for Entry
State Economic and Trade Commission of Foreign Trade and Economic
Cooperation of the State Environmental Protection Administration of Customs
State Administration for Industry and State Administration of Quality Technology
Exit Inspection and Quarantine Bureau of Supervision
Notice on Strengthening the Administration of Import of titanium production operations to rectify the order of
SETC Trade [ 1999 ] No. 1164
Provinces, autonomous regions, municipalities , separately listed cities and Xinjiang Production and Construction Corps (economic commissions , Economic Commission ) , Office of Foreign Trade ( Commission, Council ) , Guangdong Customs , directly under the Customs , the Environmental Protection Agency , Administration for Industry quality and Technical Supervision , Inspection and Quarantine Bureau directly under the immigration :
As a new high-performance titanium rare quality , cutting-edge technology is indispensable for defense and critical and supportive materials. Since the founding of the great support in the country , China's titanium industry developed rapidly , becoming one of the few countries in the world capable of producing titanium , product quality has reached the international advanced level , especially aviation titanium alloy material , a world leader , enjoys a certain reputation in the international arena . But in recent years , a number of companies and individuals in driving local interests, a large number of illegal import of scrap titanium through border trade and smuggling and other forms , resulting in domestic sunrui Titanium alloy valve production, circulation disorder, seriously affect the normal development of China's titanium industry . To promote the healthy development of domestic titanium industry , to ensure the normal operation of domestic titanium producers , according to the relevant laws and regulations of the country , decided to strengthen the management and consolidation of imported titanium titanium production , operation order . Relevant issues are hereby notified as follows:
First, strengthen titanium import management
( A ) the titanium , titanium alloy , titanium alloy shredded scrap ( specific heading annex ) as the focus of sensitive goods imports , increase customs inspection efforts. Meanwhile, the focus of the trial price of titanium products as customs , the customs at trial must be strictly in accordance with relevant provisions of trial , to prevent price frauds .
In Xinjiang , Inner Mongolia, Heilongjiang various ports , the investigation focused on the implementation of regulatory control , and resolutely crack down by pseudo- reported imports of titanium and other ways of concealing illegal behavior.
Intensify efforts to combat smuggling of titanium , titanium imports of violations and smuggling cases , and resolutely punished according to law .
( B) the strict implementation of the National Environmental Protection Agency , the Ministry of Foreign Trade and Economic Cooperation , Customs, State Administration for Industry and Commerce , the State Administration of 1996 jointly issued "on the promulgation < Provisional Regulations on Administration of Environmental Protection Waste Import " notice " ( environmental Control [ 1996 ] No. 204 ) of the relevant provisions prohibited titanium scrap , scrap titanium alloy , titanium alloy scrap imports, the state environmental protection department shall not issue " waste import approval certificate ." Right to scrap iron and steel, electrical appliances and other scrap metal imports in nominal imports of titanium or entrained units and individuals , once discovered , in accordance with the relevant provisions of the punishment.
Import and export operation rights and have the right to operate cross-border trade enterprises are not allowed to import or import agent titanium scrap , scrap titanium alloy , titanium alloy scrap , once discovered , is handled by the foreign trade department according to relevant regulations , the circumstances are serious business , cancel or suspend its right to operate import and export business.
( 3) to titanium , titanium alloy product catalog to include statutory inspection by the State Administration for Entry for the implementation of the statutory inspection of imported titanium , do not ban the import of compliant products .
Second, to strengthen titanium processing production management
Enterprises for the production of titanium production license system , the quality and technical supervision departments providers nonferrous metals industry management department of the existing producers of titanium titanium production licenses issued . Unlicensed businesses and individuals are not allowed to production and processing of titanium and its products .
Quality and technical supervision departments in conjunction with the non-ferrous metal industry management departments to strengthen the production and processing of titanium product quality supervision and inspection , who found adulterated, or impurities, shoddy, substandard goods as well as qualified products use imported scrap titanium titanium raw materials , according to the relevant regulations of the State to punish .
Third, rectify market order flow titanium
State sales and acquisitions of titanium metal titanium , titanium alloy , titanium alloy scrap ( including unwrought titanium , powder , profiles , etc. ) of a unified management . Titanium ventures have been set up after the State Economic and Trade Commission or its authorized approval, prior to June 1, 2000 to the industrial and commercial administrative authorities for re-registration . The new application for the establishment of titanium enterprises approved by the State Economic and Trade Commission or its authorized units , the industry and commerce administration authorities for registration . Without the approval and registration of , any enterprise or individual shall engage in business activities titanium .
Recently, the State aerospace investment castings Administration for Industry and Commerce in conjunction with the quality and technical supervision departments of Baoji , Shenyang two centralized straighten titanium market , strictly regulate the processing and marketing behavior of titanium products , strengthen quality supervision of related products.
All relevant departments should actively cooperate , to work together to strengthen titanium import management and good rectification work on titanium production, operation order.
From the date of the notice issued by the Executive .
Titanium alloy valve Memory alloys for artificial heart
Memory alloy is an atomic arrangement is very rules into martensite is less than 0.5% by volume of phase change alloy . This alloy will be deformed under an external force when the external force is removed, under certain temperature conditions , can restore the original shape. Because it has more than a million times to restore function, Aerospace titanium castings so called " memory alloys ." Of course it is not like the human brain thinking and memory , more accurately should be called " shape memory alloys ." In addition, the memory alloy also has a non-magnetic, wear and corrosion , non-toxic advantages, so widely used. Scientists have now discovered dozens of different memory alloys , such as titanium - nickel alloy, gold - cadmium alloy, copper - zinc alloy.
What is memory alloy 1870s , the world there is a materials science with alloy " memory" shape function . Memory is a rather special alloy metal bars , it can easily be bent , we put it in the container of hot water aquarium , metal strips rushed forward ; put it into cold water , the metal strip is restored the status quo. Container of cold water in the aquarium , the stretch of a spring , when the spring into the hot water , springs and automatically folded up . Cold water in the spring to restore its original state , while in hot water , it will shrink , spring can be an unlimited number of stretching and shrinking , shrinking again opened. The memory consists of an intelligent made of metal , the microstructure of which has two relatively stable at high temperatures of the alloy can be turned into any shape you want, the alloy at lower temperatures can be stretched , but if it is reheated , it will remember its original shape , and change back. This material is called memory metal (memory metal). It is mainly a nickel titanium material. For example , a helical superalloy, after high temperature annealing , which is in the shape of a spiral state. At room temperature , that is forced to use a lot of effort to straighten it , but as long as it is heated to a certain " abnormal temperature ," which seemed to root alloy remembered something, now restored to its original helical shape . How is this going ? Did alloy also has a kind of human memory ? Original not the case ! It's just the use of certain alloys law changes the crystal structure in the solid state with temperature only. For example , a nickel - titanium alloy 40oC 40oC above and below the crystal structure is different, but the temperature change in the vertical 40oC , will be contracted or expanded metal , such that its shape is changed . Here , 40oC is a nickel - titanium shape memory alloy "abnormal temperature ." Various alloys have their own perverted temperature. Abnormal high temperature superalloys above that . At high temperatures it is spirally formed in a stable state . At room temperature when it forcibly straightened, it is in an unstable state , sunrui Titanium alloy valve so long as it is heated to a temperature of metamorphosis , it is immediately restored to the spiral shape of the original is in a stable state . Classification and application of shape memory alloy can be divided into three types: ( 1 ) one-way shape memory alloy memory effect deformation at low temperature before heating the deformed shape recoverability , which exists only in the heating process of shape memory One way is called memory effect . ( 2 ) Two-way memory effect of certain alloys with shape recovery temperature heating , cooling can restore the shape of the low temperature phase , called the two-way memory effect. ( 3 ) recovery throughout the high-temperature phase shape memory effect heating , cooling into the same shape and the shape of the opposite orientation of the low-temperature phase , called the whole memory effect. Three kinds of memory effect is shown below. Has been successfully developed TiNi shape memory alloy based shape memory alloys, copper-based shape memory alloys , iron-based shape memory alloys. The earliest reports of the shape memory effect and Read by Chang et al made in 1952 . They observed Au-Cd alloy reversible phase transformation . Later in the Cu-Zn alloys also found the same phenomenon, but did not attract widespread attention . Until 1962 , Buehler and his collaborators observed with macroscopic shape memory effects such as changes in the atomic ratio of TiNi alloy , it attracted the attention of materials science and industry . By the early 1970s , CuZn, CuZnAl, CuAlNi also found in other alloys with shape memory effect martensitic transformation related . For decades, research on shape memory alloy has gradually become an important issue of international conferences and phase change materials conferences , and has held a number of symposia , and constantly enrich and improve the martensitic aerospace investment castings transformation theory . In theory deepening , while the application of shape memory alloys have also made considerable progress, its scope of application involves many areas of mechanical , electronic, chemical , aerospace , energy and medical. Specific applications of shape memory alloys below. Industrial applications: ( 1 ) the use of one-way shape memory effect of a one-way shape recovery . Such as pipe fittings, antenna , rings and so on. ( 2 ) extrinsic two-way memory recovery. Namely the use of one-way shape memory effect and lifting to do with the temperature outside help repeated actions, such as heat-sensitive components, robots, terminals , etc. ( 3 ) intrinsic two-way memory recovery. Namely the use of two-way memory effect with temperature elevating do repeated actions, such as heat engines , thermal components. But such applications faster memory decay , poor reliability , not commonly used. ( 4 ) ultra- flexible application . Such as springs , terminal, eyeglass frames and so on. Medical Applications : biocompatibility TiNi alloy good use of its shape memory effect and superelasticity medical instances considerable . If the filter thrombosis , spinal orthopedic rods, tooth orthopedic wire, cerebral aneurysm clips, plates , intramedullary nail , artificial joints, contraceptive devices , cardiac repair components, artificial kidneys using a micro- pumps. Tech applications Outlook: The 20th century was the era of mechanical and electrical science . Sensing - IC - driving is the most typical mechanical and electronic control systems, but the complexity and huge . Shape memory materials both sensing and driven dual function , the control system can achieve miniaturization and intelligent robots such as holograms , ultra- millimeter micro robots. The 21st century will be the era of e- learning materials . Action shape memory alloy robot addition to temperature conditions without any environmental impact is expected in high-tech fields reactors, accelerators , space laboratories flourish. Memory alloy spoke alloys, of course, talk about the most interesting alloys - memory alloy . Metal has a memory , an accidental discovery : the early 1960s , a research team from the U.S. Navy led to some of the warehouse nitinol wire experiments , they found that these alloy wire winding , very easy to use , so he took these alloy wire a root straightened. During the test , a strange phenomenon , they found that when the temperature rose to a certain value , which has been straightened nitinol wire suddenly restored to its original state bent , they are good at observing the heart, and repeated done several tests , the results have confirmed these filaments do ? "memory ." The discovery of Naval Research , and aroused great interest in the scientific community , a large number of scientists have conducted in-depth research . Found that zinc alloy , copper-aluminum -nickel alloy , copper-molybdenum -nickel alloy , zinc alloy, copper and gold also have this strange ability . It may be in a certain range , according to the need to change the shape of these alloys to a particular temperature, they automatically return to their original shape , and this " change - recovery " may be repeated several times , regardless of how changes they always remember the shape of his own time , to this temperature , it is no less to the prototype reproduction. It is called the shape memory effect of this phenomenon , the metal having such a shape memory effect is called a shape memory alloy , referred to as memory alloy . Why are these alloys can have such a shape memory effect ? How they remember their original shape ? With the general theory of metallic bonds , free electron theory is difficult to explain the effect of this memory alloy . Memory alloy under certain temperature conditions can be restored to original shape for sports extranuclear - movement with temperature changes , provides an excellent example. It is due to the formation of the alloy at high temperature of the liquid metal melt each other , since the structure of the liquid metal element rejection , resulting in the structure of another metal element and the structure of each element of this element uniform solidification , its microstructure is ordered different types of structure element proportional to the electromagnetic force is the main object of the alloy constituting the cohesion . The electromagnetic force is formed by the valence and electronic operation of the electronic operating rate changes with temperature , so the electromagnetic force ( size, direction , action point ) is also inside the object temperature conditions. The resulting internal forces of metal objects with temperature changes , but these changes within a small range of temperature difference is not obvious , only performance only in the larger temperature changes ( several hundred degrees C) . Force in the general metal , can be plastically deformed as a wire is bent , the bending portion , the electromagnetic force by the external disturbance , resulting in operation of an electromagnetic plane and force electrons to the valence micro adjustment , a plastic deformation completed . Due to the different types of memory alloy structural element uniform blending with each other , despite the different size of the structure element tall, electromagnetic force , but each has its own price and speed up the operation , under certain temperature conditions adjacent peace and quiet . After the external force , the electromagnetic force of the external disturbance , and the valence electrons run to the plane of trace angle adjustment , the object is plastically deformed , in this plastic deformation , the price and the adjustment operation of the electronic part is not stretched . When the rate of change of temperature change with current prices and electrons when the temperature returns to the refreshing phase of development (transition temperature ) conditions , and does not stretch the valence electrons immediately run back to the time rate of change along the electromagnetic force , the adjacent structural element of price and running are also adjusted accordingly , the entire stretch back to the original state , so the whole object also return to the original state. This is the memory of the process memory alloy . In fact, the memory metal has long been found : a straight wire bent to a right angle (90 °), a release , it is necessary to restore it to form an angle larger than 90 ° . Put a bent wire straightening , it must fold to over 180 ° and then released, so that it can just return to the straight state, which is the Chinese idiom spoken overkill. There is a better memory alloy spring , ( talking about here is a steel spring , steel is an iron -carbon alloy ) spring firmly remember their shape , force a withdrawal , immediately return to their original appearance, only a wide temperature memory spring , so there is not a specific memory alloys transition temperature, which has some special functions . With the memory alloy deformation function at a particular temperature , the temperature can produce a variety of devices, the temperature control circuit can be produced , thermostatic door , temperature of the pipe connection . People have made use of automatic memory alloy fire hydrant - fire temperature, memory alloy deformation, so that the valve opens, water spray fire. Making a connection to connect the mechanical parts , pipes , air refueling aircraft interface is the use of a shape memory alloy - two oil pipes tacking , the use of electric heating temperature change , the interface memory alloy deformation, so that the interface tight dripping ( oil ) does not leak . Making the area of several hundred square meters of space station antenna from Fair - first made large parabolic antennas or planar , folded into a ball on the ground, with the spacecraft to the space , the temperature changes , since the development of a large area and the original shape. Memory alloys have been to dozens of current development in the aerospace, military, industrial, agricultural , medical and other fields have a purpose , and the development trend is very impressive, it is grand plans for the benefit of mankind.
Shape memory alloys have been found so far a dozen memory alloy system. Include Au-Cd, Ag-Cd, Cu-Zn, Cu-Zn-Al, Cu-Zn-Sn, Cu-Zn-Si, Cu-Sn, Cu-Zn-Ga, In-Ti, Au-Cu-Zn , NiAl, Fe-Pt, Ti-Ni, Ti-Ni-Pd, Ti-Nb, U-Nb and Fe-Mn-Si , etc.
Application memory alloy application memory alloy is widely used. For example, the fastening pin machinery, fittings, fire alarm on electronic equipment , connectors , integrated circuits, soldering , artificial heart valves for medical , chiropractic stick, skull repair surgery, orthopedic and oral teeth mandible repair surgery. It will also play a magical performance in a communications satellite , color TV , temperature controllers and toys , etc., will also be new material on all fronts , modern maritime, aviation , aerospace , transportation , textile and so on.
Memory alloy pipe has been used in combination with automatic control , the sleeve may be made of shape memory alloy instead of welding , is in the low temperature expansion of the tube to approximately 4% of the full , a socket assembly with a heated , shrinkage of the sleeve restore the prototype , form a tight engagement . U.S. Navy aircraft hydraulic system uses a 100,000 such joints, oil spills and damage over the years never happened . Ship and submarine oil pipeline damage , sunrui titanium alloy coils repair it with a shape memory alloy fittings, very convenient. In some parts of the inconvenience of construction , the pin made of shape memory alloy , into the hole is heated to separate the trailing end automatically curl to form single assembly .
Memory alloy is particularly suitable for thermo-mechanical and automatic temperature control , automatic opening and closing has made room arm can open the windows are in the sunshine during the day , automatically turns off when the night temperature drops. Memory alloy heat engine designs are also a lot that they can be in with a low temperature difference between the two media work , so as to take advantage of industrial cooling water , nuclear reactor heat, ocean thermal and solar power opened up new avenues . Now the problem is widespread efficiency is not high, only 4 % to 6% , to be further improved .
Memory alloys in medical applications is also very compelling. E.g., the bone with the bone plate , not only can two fixing broken bones , and the recovery of the original shape of the compression force is generated , forcing the broken bones are joined together . After straightening teeth using dental wire , long clip ligation of cerebral aneurysms and vas deferens , with the support plate straightening the spine , are implanted in the human body temperature by the action starts, thrombus filter is also a new product memory alloy . After being straightened filter implanted vein , will be gradually restored into a network , thereby preventing clot 95% flow to the heart and lungs.
Artificial heart is a more complex structure of the organ , muscle fibers of the elastic memory alloy thin film made of ventricular cooperate to mimic ventricular contraction . Now water is pumped been successful.
Since memory alloy is a " life has alloy " , use it at a certain temperature changes shape , you can design all kinds of self-control devices , its use is expanding . The first application of shape memory alloy pipe fittings in and fasteners . A shape memory alloy is processed into an outer diameter smaller than the internal diameter of the pipe to be connected to the casing 4% , at liquid nitrogen temperature and then expanding the sleeve diameter of about 8% , this will be removed from the cannula assembly when the liquid nitrogen , the desire inserted from both ends of the tube connection . When the temperature was raised to room temperature , i.e., the sleeve forming a holding seal shrinkage . This connection can be in close contact with anti-leakage , far better than welding , especially suitable for aviation, aerospace , nuclear industry and submarine pipelines and other dangerous situations. The most promising application memory alloys in aerospace technology . July 20, 1969 , "Apollo" 11 lunar module landed on the moon , the first human landing on the moon to achieve the dream of traveling . After the astronauts landing on the moon , on the moon a few meters in diameter placed a large hemispherical antenna for transmitting and receiving information to Earth . A few meters from a large antenna mounted on the tiny lunar module sent into space inside . Antenna that was just invented near memory alloy used. Under normal circumstances, the first predetermined requirements of good memory alloy material with a very thin , then lower the temperature to press it into a ball , bring the day to go into the lunar module . Into the lunar surface after the temperature rise in the sunlight , when it reaches the transition temperature , antennas and " mind" from their original appearance , becomes a huge domed . At present, the shape memory effect and superelasticity has been widely used in various fields of medicine and life . Thrombus filter manufacturing , spinal orthopedic rods, plates , artificial joints, women bra , artificial heart and so on. Can also be widely used in a variety of automatic regulation and control devices. Shape memory films and filaments may be the ideal material for future ultra- miniature robots and robots. Especially its light weight, high strength and corrosion resistance makes it highly popular in various fields .
What is memory alloy 1870s , the world there is a materials science with alloy " memory" shape function . Memory is a rather special alloy metal bars , it can easily be bent , we put it in the container of hot water aquarium , metal strips rushed forward ; put it into cold water , the metal strip is restored the status quo. Container of cold water in the aquarium , the stretch of a spring , when the spring into the hot water , springs and automatically folded up . Cold water in the spring to restore its original state , while in hot water , it will shrink , spring can be an unlimited number of stretching and shrinking , shrinking again opened. The memory consists of an intelligent made of metal , the microstructure of which has two relatively stable at high temperatures of the alloy can be turned into any shape you want, the alloy at lower temperatures can be stretched , but if it is reheated , it will remember its original shape , and change back. This material is called memory metal (memory metal). It is mainly a nickel titanium material. For example , a helical superalloy, after high temperature annealing , which is in the shape of a spiral state. At room temperature , that is forced to use a lot of effort to straighten it , but as long as it is heated to a certain " abnormal temperature ," which seemed to root alloy remembered something, now restored to its original helical shape . How is this going ? Did alloy also has a kind of human memory ? Original not the case ! It's just the use of certain alloys law changes the crystal structure in the solid state with temperature only. For example , a nickel - titanium alloy 40oC 40oC above and below the crystal structure is different, but the temperature change in the vertical 40oC , will be contracted or expanded metal , such that its shape is changed . Here , 40oC is a nickel - titanium shape memory alloy "abnormal temperature ." Various alloys have their own perverted temperature. Abnormal high temperature superalloys above that . At high temperatures it is spirally formed in a stable state . At room temperature when it forcibly straightened, it is in an unstable state , sunrui Titanium alloy valve so long as it is heated to a temperature of metamorphosis , it is immediately restored to the spiral shape of the original is in a stable state . Classification and application of shape memory alloy can be divided into three types: ( 1 ) one-way shape memory alloy memory effect deformation at low temperature before heating the deformed shape recoverability , which exists only in the heating process of shape memory One way is called memory effect . ( 2 ) Two-way memory effect of certain alloys with shape recovery temperature heating , cooling can restore the shape of the low temperature phase , called the two-way memory effect. ( 3 ) recovery throughout the high-temperature phase shape memory effect heating , cooling into the same shape and the shape of the opposite orientation of the low-temperature phase , called the whole memory effect. Three kinds of memory effect is shown below. Has been successfully developed TiNi shape memory alloy based shape memory alloys, copper-based shape memory alloys , iron-based shape memory alloys. The earliest reports of the shape memory effect and Read by Chang et al made in 1952 . They observed Au-Cd alloy reversible phase transformation . Later in the Cu-Zn alloys also found the same phenomenon, but did not attract widespread attention . Until 1962 , Buehler and his collaborators observed with macroscopic shape memory effects such as changes in the atomic ratio of TiNi alloy , it attracted the attention of materials science and industry . By the early 1970s , CuZn, CuZnAl, CuAlNi also found in other alloys with shape memory effect martensitic transformation related . For decades, research on shape memory alloy has gradually become an important issue of international conferences and phase change materials conferences , and has held a number of symposia , and constantly enrich and improve the martensitic aerospace investment castings transformation theory . In theory deepening , while the application of shape memory alloys have also made considerable progress, its scope of application involves many areas of mechanical , electronic, chemical , aerospace , energy and medical. Specific applications of shape memory alloys below. Industrial applications: ( 1 ) the use of one-way shape memory effect of a one-way shape recovery . Such as pipe fittings, antenna , rings and so on. ( 2 ) extrinsic two-way memory recovery. Namely the use of one-way shape memory effect and lifting to do with the temperature outside help repeated actions, such as heat-sensitive components, robots, terminals , etc. ( 3 ) intrinsic two-way memory recovery. Namely the use of two-way memory effect with temperature elevating do repeated actions, such as heat engines , thermal components. But such applications faster memory decay , poor reliability , not commonly used. ( 4 ) ultra- flexible application . Such as springs , terminal, eyeglass frames and so on. Medical Applications : biocompatibility TiNi alloy good use of its shape memory effect and superelasticity medical instances considerable . If the filter thrombosis , spinal orthopedic rods, tooth orthopedic wire, cerebral aneurysm clips, plates , intramedullary nail , artificial joints, contraceptive devices , cardiac repair components, artificial kidneys using a micro- pumps. Tech applications Outlook: The 20th century was the era of mechanical and electrical science . Sensing - IC - driving is the most typical mechanical and electronic control systems, but the complexity and huge . Shape memory materials both sensing and driven dual function , the control system can achieve miniaturization and intelligent robots such as holograms , ultra- millimeter micro robots. The 21st century will be the era of e- learning materials . Action shape memory alloy robot addition to temperature conditions without any environmental impact is expected in high-tech fields reactors, accelerators , space laboratories flourish. Memory alloy spoke alloys, of course, talk about the most interesting alloys - memory alloy . Metal has a memory , an accidental discovery : the early 1960s , a research team from the U.S. Navy led to some of the warehouse nitinol wire experiments , they found that these alloy wire winding , very easy to use , so he took these alloy wire a root straightened. During the test , a strange phenomenon , they found that when the temperature rose to a certain value , which has been straightened nitinol wire suddenly restored to its original state bent , they are good at observing the heart, and repeated done several tests , the results have confirmed these filaments do ? "memory ." The discovery of Naval Research , and aroused great interest in the scientific community , a large number of scientists have conducted in-depth research . Found that zinc alloy , copper-aluminum -nickel alloy , copper-molybdenum -nickel alloy , zinc alloy, copper and gold also have this strange ability . It may be in a certain range , according to the need to change the shape of these alloys to a particular temperature, they automatically return to their original shape , and this " change - recovery " may be repeated several times , regardless of how changes they always remember the shape of his own time , to this temperature , it is no less to the prototype reproduction. It is called the shape memory effect of this phenomenon , the metal having such a shape memory effect is called a shape memory alloy , referred to as memory alloy . Why are these alloys can have such a shape memory effect ? How they remember their original shape ? With the general theory of metallic bonds , free electron theory is difficult to explain the effect of this memory alloy . Memory alloy under certain temperature conditions can be restored to original shape for sports extranuclear - movement with temperature changes , provides an excellent example. It is due to the formation of the alloy at high temperature of the liquid metal melt each other , since the structure of the liquid metal element rejection , resulting in the structure of another metal element and the structure of each element of this element uniform solidification , its microstructure is ordered different types of structure element proportional to the electromagnetic force is the main object of the alloy constituting the cohesion . The electromagnetic force is formed by the valence and electronic operation of the electronic operating rate changes with temperature , so the electromagnetic force ( size, direction , action point ) is also inside the object temperature conditions. The resulting internal forces of metal objects with temperature changes , but these changes within a small range of temperature difference is not obvious , only performance only in the larger temperature changes ( several hundred degrees C) . Force in the general metal , can be plastically deformed as a wire is bent , the bending portion , the electromagnetic force by the external disturbance , resulting in operation of an electromagnetic plane and force electrons to the valence micro adjustment , a plastic deformation completed . Due to the different types of memory alloy structural element uniform blending with each other , despite the different size of the structure element tall, electromagnetic force , but each has its own price and speed up the operation , under certain temperature conditions adjacent peace and quiet . After the external force , the electromagnetic force of the external disturbance , and the valence electrons run to the plane of trace angle adjustment , the object is plastically deformed , in this plastic deformation , the price and the adjustment operation of the electronic part is not stretched . When the rate of change of temperature change with current prices and electrons when the temperature returns to the refreshing phase of development (transition temperature ) conditions , and does not stretch the valence electrons immediately run back to the time rate of change along the electromagnetic force , the adjacent structural element of price and running are also adjusted accordingly , the entire stretch back to the original state , so the whole object also return to the original state. This is the memory of the process memory alloy . In fact, the memory metal has long been found : a straight wire bent to a right angle (90 °), a release , it is necessary to restore it to form an angle larger than 90 ° . Put a bent wire straightening , it must fold to over 180 ° and then released, so that it can just return to the straight state, which is the Chinese idiom spoken overkill. There is a better memory alloy spring , ( talking about here is a steel spring , steel is an iron -carbon alloy ) spring firmly remember their shape , force a withdrawal , immediately return to their original appearance, only a wide temperature memory spring , so there is not a specific memory alloys transition temperature, which has some special functions . With the memory alloy deformation function at a particular temperature , the temperature can produce a variety of devices, the temperature control circuit can be produced , thermostatic door , temperature of the pipe connection . People have made use of automatic memory alloy fire hydrant - fire temperature, memory alloy deformation, so that the valve opens, water spray fire. Making a connection to connect the mechanical parts , pipes , air refueling aircraft interface is the use of a shape memory alloy - two oil pipes tacking , the use of electric heating temperature change , the interface memory alloy deformation, so that the interface tight dripping ( oil ) does not leak . Making the area of several hundred square meters of space station antenna from Fair - first made large parabolic antennas or planar , folded into a ball on the ground, with the spacecraft to the space , the temperature changes , since the development of a large area and the original shape. Memory alloys have been to dozens of current development in the aerospace, military, industrial, agricultural , medical and other fields have a purpose , and the development trend is very impressive, it is grand plans for the benefit of mankind.
Shape memory alloys have been found so far a dozen memory alloy system. Include Au-Cd, Ag-Cd, Cu-Zn, Cu-Zn-Al, Cu-Zn-Sn, Cu-Zn-Si, Cu-Sn, Cu-Zn-Ga, In-Ti, Au-Cu-Zn , NiAl, Fe-Pt, Ti-Ni, Ti-Ni-Pd, Ti-Nb, U-Nb and Fe-Mn-Si , etc.
Application memory alloy application memory alloy is widely used. For example, the fastening pin machinery, fittings, fire alarm on electronic equipment , connectors , integrated circuits, soldering , artificial heart valves for medical , chiropractic stick, skull repair surgery, orthopedic and oral teeth mandible repair surgery. It will also play a magical performance in a communications satellite , color TV , temperature controllers and toys , etc., will also be new material on all fronts , modern maritime, aviation , aerospace , transportation , textile and so on.
Memory alloy pipe has been used in combination with automatic control , the sleeve may be made of shape memory alloy instead of welding , is in the low temperature expansion of the tube to approximately 4% of the full , a socket assembly with a heated , shrinkage of the sleeve restore the prototype , form a tight engagement . U.S. Navy aircraft hydraulic system uses a 100,000 such joints, oil spills and damage over the years never happened . Ship and submarine oil pipeline damage , sunrui titanium alloy coils repair it with a shape memory alloy fittings, very convenient. In some parts of the inconvenience of construction , the pin made of shape memory alloy , into the hole is heated to separate the trailing end automatically curl to form single assembly .
Memory alloy is particularly suitable for thermo-mechanical and automatic temperature control , automatic opening and closing has made room arm can open the windows are in the sunshine during the day , automatically turns off when the night temperature drops. Memory alloy heat engine designs are also a lot that they can be in with a low temperature difference between the two media work , so as to take advantage of industrial cooling water , nuclear reactor heat, ocean thermal and solar power opened up new avenues . Now the problem is widespread efficiency is not high, only 4 % to 6% , to be further improved .
Memory alloys in medical applications is also very compelling. E.g., the bone with the bone plate , not only can two fixing broken bones , and the recovery of the original shape of the compression force is generated , forcing the broken bones are joined together . After straightening teeth using dental wire , long clip ligation of cerebral aneurysms and vas deferens , with the support plate straightening the spine , are implanted in the human body temperature by the action starts, thrombus filter is also a new product memory alloy . After being straightened filter implanted vein , will be gradually restored into a network , thereby preventing clot 95% flow to the heart and lungs.
Artificial heart is a more complex structure of the organ , muscle fibers of the elastic memory alloy thin film made of ventricular cooperate to mimic ventricular contraction . Now water is pumped been successful.
Since memory alloy is a " life has alloy " , use it at a certain temperature changes shape , you can design all kinds of self-control devices , its use is expanding . The first application of shape memory alloy pipe fittings in and fasteners . A shape memory alloy is processed into an outer diameter smaller than the internal diameter of the pipe to be connected to the casing 4% , at liquid nitrogen temperature and then expanding the sleeve diameter of about 8% , this will be removed from the cannula assembly when the liquid nitrogen , the desire inserted from both ends of the tube connection . When the temperature was raised to room temperature , i.e., the sleeve forming a holding seal shrinkage . This connection can be in close contact with anti-leakage , far better than welding , especially suitable for aviation, aerospace , nuclear industry and submarine pipelines and other dangerous situations. The most promising application memory alloys in aerospace technology . July 20, 1969 , "Apollo" 11 lunar module landed on the moon , the first human landing on the moon to achieve the dream of traveling . After the astronauts landing on the moon , on the moon a few meters in diameter placed a large hemispherical antenna for transmitting and receiving information to Earth . A few meters from a large antenna mounted on the tiny lunar module sent into space inside . Antenna that was just invented near memory alloy used. Under normal circumstances, the first predetermined requirements of good memory alloy material with a very thin , then lower the temperature to press it into a ball , bring the day to go into the lunar module . Into the lunar surface after the temperature rise in the sunlight , when it reaches the transition temperature , antennas and " mind" from their original appearance , becomes a huge domed . At present, the shape memory effect and superelasticity has been widely used in various fields of medicine and life . Thrombus filter manufacturing , spinal orthopedic rods, plates , artificial joints, women bra , artificial heart and so on. Can also be widely used in a variety of automatic regulation and control devices. Shape memory films and filaments may be the ideal material for future ultra- miniature robots and robots. Especially its light weight, high strength and corrosion resistance makes it highly popular in various fields .
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