Performance and titanium alloys are widely used in industry

Titanium because of its high strength, heat resistance, corrosion resistance, widely applied in industry . Especially in aviation, aerospace , shipbuilding and other industries , mostly used in the manufacture of titanium alloy key components , its performance is good or bad usually determines the level of the product . Therefore , national research institutions to put a lot of manpower, material and financial resources to carry out its melting alloys and equipment , forming process research and development , writing papers , and many thousands of monographs . However, the study of titanium companies  process with little , limited studies have limited studied. Titanium because of its high melting point, chemical activity , thermal properties between the elements of the big difference , so the smelting process of melt composition and temperature control is very difficult, and the melt composition and temperature directly determine the quality of titanium casting companies . Therefore , to identify qualitative and quantitative variation of melt composition, temperature and process parameters , alloy itself between thermal parameters have important practical significance for guiding titanium melting , smelting practice for other alloys also have important reference value.

The role of titanium ingot segregation effects

Seen from the front , consumable arc melting , the solidification of titanium ingots from the bottom of the ingot in the order gradually to - wide solidification solidification process is in order. As a result, some of the titanium alloy ingot impurity elements to different parts of the ingot are regularly distributed , resulting in segregation effects. The principle of effective government is also purified metal smelting area . It makes titanium ingots alloying elements or impurities in small ingots showing the distribution area segregation.
    Segregation effect occurs with titanium ingot ( or metal sticks ) impurities ( or alloying elements ) equilibrium distribution constant K0 relevant ; segregation effects arising after the gradual solidification of the cash borrowed from the theory of a titanium ingots left to be addressed on that theory when the order reported titanium ingot ingot Titanium Casting Manufacturer solidification small impurity distribution diagram . The actual status of titanium ingots similar.
    However , the rapid melting process flexor directional solidification process , the impurity diffusion between the two phases in the shelter group can not reach equilibrium , so it's not a distribution constant K0, segregation of some small effect . When titanium melting, segregation should be a purifying effect of the role , as long as the use of light ingots , you can reduce the effects of impurities.
    Secondary smelting produce titanium casting factory consumable content of impurities TA2 pure milled raw material ingot Table relationship , which is the average of 100 titanium ingots . As can be seen from the table, iron , titanium ingot and the nitrogen concentration of the titanium sponge has not changed , the purification effect of sky ; silicon, carbon and oxygen increased slightly , and no purification effect, but in the smelting process is increased impurity contamination volume ; Lee hydrogen chloride purification obvious effect , do not hold the product in a reduced number of chlorine and level . It also shows that the main role of vacuum distillation . Both the total amount of impurities from the point of view , slightly lower than the titanium ingot of titanium sponge impurities, by lowering the melting sponge drink chlorine , and slightly increases the oxygen and other impurities. In short , a slight increase in the purity of titanium , but it remains in a substantially horizontal magnitude .

Of uniform standards and methods of evaluation of aerospace titanium castings retardant properties

Of uniform standards and methods of evaluation of titanium flame retardant properties. Properly evaluate flame retardant properties of titanium alloys is one of the key technologies of flame Titanium precision castings  titanium alloys, including combustion simulation methods and testing techniques. Currently, the evaluation method on the flame retardancy is no uniform standard, countries have adopted different methods of testing. So retardant performance evaluation method to develop a unified standard titanium will effectively promote the exchange of national retardant titanium. (2) improve the overall mechanical properties of Titanium precision castings retardant. Compared with flame titanium, titanium alloy retardant poor mechanical properties, the working temperature is lower. On how to further improve the mechanical properties of the(3) reduce the flame titanium costs. Resistant Titanium alloy sheets contains a lot of noble metal elements V, resulting in higher costs, limiting its applications. Domestic scholars have adopted partial substitution of lower-priced Mo V for a certain amount of research to try. alloy of the need for a deeper study.

Modern superplastic deformation theory that grain boundary sliding is the main way of superplastic deformation

Modern superplastic deformation theory that grain boundary sliding is the main way of superplastic deformation, diffusion and dislocation motion inside the grain and the grain boundary is the main coordinating mechanism of grain boundary sliding. Superplastic forming of titanium alloy pump  B-phase diffusion creep or dislocation creep dominated: A phase to the grain boundary sliding-based, coordinated jointly by diffusion and bit dislocation motion; A and B are two phases flow to A and B phase boundary migration to complete. Hydrogen in the titanium alloy superplastic forming :( mainly plays a role in the following) was added to increase the diffusivity of hydrogen in the alloy elements, resulting in enhanced B-phase diffusion slip A creep and titanium casting process intergranular phase. (2) the diffusion of hydrogen activated dislocation pinning promote the climb and slide dislocations, improved sliding capacity of B grains, the coordinating role of dislocations in favor of A / A grain boundary sliding requested. (3) hydrogen-induced weak bond effect, reducing the diffusion activation energy, enhanced atomic diffusion capacity, improve the superplastic flow capacity. (4) the Titanium alloy valve addition of hydrogen significantly reduces B \ A + B transition temperature, increase the volume fraction of the B phase, a direct result of the increase and decrease the flow stress of the plastic, so that the titanium alloy can be deformed at a lower temperature and higher deformation rates were superplastic forming.

As the representative of the research and production facilities

As the representative of the United States Bureau of Mines research and production facilities for titanium investment casting technology in-depth research, development of the melting and casting process is suitable for titanium , which is a low-cost processing and forming of Titanium alloy valve opened up a new path. As a method of casting forming complex shapes can be directly manufactured parts eliminates a lot of the subsequent processing steps , thus increasing material utilization and reduce titanium alloy casting manufacturing costs.Titanium alloy valve in the aerospace engine usage and comparison of forgings , can be seen, Titanium alloy valve with clear growth trend will gradually reach the amount of titanium forgings for each equivalent level. In particular, the application of cast titanium valve in civilian areas , for example, if the casting can be mass produced with great golf club head , which promote the use and development of cast itanium alloy valve. In all system shell process parameters on shell quality and ultimately a greater impact on the quality of castings are: batter ingredients, namely powder -liquid ratio , dewaxing and roasting process parameters, this research labs now there are devices on the above parameters in-depth study and optimize selection.

With the memory titanium check valve deformation function at a particular temperature

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 Titanium alloy valve automatic memory alloy fire hydrant - fire temperature, memory alloy deformation, so that the titanium check 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 titanium alloy does not leak . Making the area of ​​titanium check valve 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 titanium check valve 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 titanium alloy pump trend is very impressive, it is grand plans for the titanium check valve benefit of mankind.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.

Aerospace titanium castings to the successful development of the machine

Why not see rivets it. In fact, this and related processing technology , due to the advances in technology, a large piece of aerospace titanium castings using whole body casting , extrusion and then press through a dedicated , increased density , ( the two years prior aerospace investment castings to the successful development of the machine , once media have reported that this is the aircraft fuselage presses developed specifically for ) , and finally the use of CNC machine tools hollowed out , high-precision machine tools , the entire aerospace titanium castings ( diameter may up to 3 meters ) hollowed out into the shape of the aircraft fuselage , so the aircraft do not need to cover the skin, the skin of the fuselage frame and a aerospace titanium castings are then processed , so do not see rivets.Such a process titanium valve can greatly increase the strength of the aircraft , but also improve the accuracy of processing a lot , this is a revolutionary advancement process of the aircraft fuselage . Aircraft ever built up step by step , first build a aerospace titanium castings , between the frame and bolted punch , then use a rivet on the skin . These processes entirely by hand , the precision is difficult to control , and if the bolt which does not clench or aging can aerospace titanium castings lead to serious disintegration of the entire Titanium investment castings aircraft , light can also cause skin cracking, so planes have to be done to test the static -destructive testing whether the aircraft design strength . And because of the introduction of new processing technology J20 , the whole body is one, to achieve the best strength to do after high air maneuvers lead to the disintegration of the body will no longer appear .