The first domestic dental titanium casting machine

Although the The Fourth Military Medical University and Henan Luoyang Jianxi light industry general machinery factory jointly developed the first domestic dental Titanium alloy valve, and in the domestic sales of 23 units, and laid a solid foundation for Titanium  denture in China extensively,

   But due to the Department of Stomatology crowns and bridges of the high accuracy requirement, the internal (shaft wall) fit < 73µm, marginal fit < 100 µm, there is no domestic embedding material can meet this demand.

Experimental study on pure titanium castings surface nitriding treatment

Surface modification of pure titanium castings for this study, in order to enhance its wear resistance and corrosion resistance, improve the surface color, so as to improve the performance and aesthetic effect of titanium prosthesis.

   Plasma nitriding of pure titanium casting experiment of puretitanium TA2 conventional  casting,

 mechanical polishing and then exposed to plasma nitriding furnace, glow plasma nitriding treatmentin ammonia atmosphere, glow voltage 700V, current of 13 ~ 15A, 150Pa vacuum nitriding furnace,temperature 700 C, permeability nitrogen time 1 ~ 4h, the study of plasma nitriding the pure titaniummicro hardness, wear resistance and corrosion resistance effect.

Pure titanium castings surface nitriding

Ti has good mechanical properties, chemical stability and biocompatibility, have been widely used in aerospace, marine, military and biomedical fields. Pure titanium in oral medicine is mainly used for making denture, crown and fixed bridge, orthodontic bracket,implant and titanium porcelain etc..

  Titanium  is self passivation of metal, a layer of stable and dense oxide film formed surface at room temperature, so it has good corrosion resistance. But pure titanium low hardness, wear resistance is poor, pure titanium prosthesis to function in oral BOC,titanium oxide films on the surface of friction force, shearing force under stress, prone to scratches and wear, dental caries preventive agents such as fluoride toothpaste, gel on the film also has a certain role in bad breaking.

Effects of fluoride on the corrosion resistance of pure titanium castings

Pure titanium due to good biocompatibility is widely applied in the field of oral medicine, such as titanium, titanium porcelain crown bridge bracket and titanium implant etc.. Its good biocompatibility because the pure titanium surface with a layer of compact oxide film, good chemical stability, so as to protect the pure titanium substrate from being corrosion preventing precipitation of titanium ion.

  But co existed in the fluoride ion and hydrogen ion condition, the surface of pure titanium oxide film is dissolved, the decrease of the corrosion resistance,resulted in the precipitation of titanium ion, likely to cause adverse effects on the surrounding tissue and human body.

Effects of titanium nitride coating on corrosion resistance of pure titanium castings

Pure titanium as a biological material, low density, good mechanical performance, strong corrosion resistance, good biology compatibility, so it is widely used in the field of oral medicine. However, pure titanium as the material of denture, poor wear resistance, color appearance, susceptible to fluoride corrosion.

  The academic topic related research has been conducted on the plasma nitriding / titanium nitride coating composite surface treatment, surface properties of titanium castings of biological safety, fungal adhesion properties and clinical application effect, experiment is mainly through the potentiodynamic polarization technique and ion release experiment was conducted to observe the effect of composite surface treatment of titanium castings in corrosion resistance of fluorine environment the application of dynamic.

Titanium and titanium alloy

Titanium and titanium alloy, light weight, high strength, high yield ratio, non magnetic, biologically inert, and has excellent corrosion resistance. In seawater environment, titanium and Titanium castings almost no corrosion, corrosion resistance is excellent in most chemical medium. At present, with the progress of science and technology and all walks of life to the application of new materials to increase the strength, the necessary products of Titanium castings valve as the medium of various special environment and special fluid delivery system has been used. However, the fluid medium and environmental conditions in different areas and industries are not the same, performance requirements of the material used on different titanium valve. At the same time, because of the different components of Titanium precision castings alloy valveperformance requirements are different, different process, and to reduce the cost of parts needed to use alternative materials and other factors, the material has become one of the technical problems of first consideration must be titanium valve design and manufacturing, and suffer the widespread concern and attention. Industrial pure titanium refers to non titanium alloys with different Fe, C, N, O and other impurities content.

Titanium and titanium alloy of high strength

Titanium and titanium alloy of high strength, low density and other properties make it widely used in aerospace engineering. Such as various pipeline aircraft on the extensive use of titanium tube alloy valve, Titanium castingstype relates to the cut-off valve, check valve, needle valve, plug valve, ball valve and butterfly valve. Titanium valve as the key system components conveying fluid control titanium alloy pipe, widely used in chemical engineering. Valve valve with fasteners as important component, is also very important in valve design, manufacture. Implemented in a large PTA project mass production and application. Titanium valve is widely used in chemical industry, but must pay attention to its not suitable for any chemical medium. The hydrofluoric acid, hydrochloric acid, sulfuric acid and phosphoric acid and oxalic acid, formic acid, hot concentrated three chloroacetic acid, three trifluoroacetic acid and strong corrosive aluminum chloride, have severe corrosion effect of Titanium casting and titanium alloy, titanium valve is not suitable for this kind of chemical medium, should pay attention to in use.