Alloying elements according medical titanium alloy

There are two isomeric titanium crystals: Below 882 ℃ for close-packed hexagonal structure α 

titanium, more than 882 ℃ for β titanium body-centered cubic. Alloying elements according to their 

effect on the phase transition temperature can be divided into three categories: ① stable α-phase, 

improving the phase transition temperature of the elements of α stabilizing element, aluminum, 

carbon, oxygen and nitrogen. Titanium bars‍ Which aluminum is the main alloying elements titanium, improving its 

normal temperature and high temperature strength of the alloy, reduce the proportion increased 

elastic modulus have a significant effect. ② stable β-phase, reducing the element of the phase 

transition temperature of β stabilizing element, and can be divided isomorphous and eutectoid type 

two kinds. Application of titanium alloy products, the former molybdenum, niobium, and vanadium; 

latter chromium, manganese, copper, iron, and silicon. ③ small element of the phase transition 

temperature of the neutral elements, zirconium, tin and so on. Oxygen, nitrogen, carbon and hydrogen 

are the main impurities of titanium. Oxygen and nitrogen in the α phase has a greater solubility of 

the titanium alloy has a significant strengthening effect, but the plastic down. Usually provides 

the oxygen and nitrogen content of titanium in the 0.15 to 0.2% and 0.04% to 0.05% or less, 

respectively. The solubility of hydrogen in the α phase is very small, titanium dissolved in excess 

hydride hydrogen will produce the alloy brittle. Titanium is usually controlled hydrogen content of 

0.015% or less. The hydrogen dissolved in the titanium is reversible, can be removed by vacuum 

annealing. Density copper titanium is generally about 4.5g / cm3, only 60% of steel, titanium's 

strength was close to the strength of ordinary steel, some high-strength titanium alloy structural 

strength than a lot of steel. Therefore, titanium strength (strength / density) is much larger than 

other metal structural materials. Copper titanium alloy with high strength and low density, good 

mechanical properties, titanium grade 2 sheet‍ good toughness and corrosion resistance. In addition, the process performance 

titanium poor machining difficulties in thermal processing, it is very easy to absorb nitrogen 

hydroxide carbon and other impurities. There are poor abrasion resistance, complex production 

process. Titanium is mainly used for the production of aircraft engine compressor components, 

followed by the structure rockets, missiles and high-speed aircraft. Light quality titanium and 

titanium alloys, high-strength, yield ratio, non-magnetic, there is biologically inert and has 

excellent corrosion resistance. In marine environments, titanium and titanium alloys almost no 

corrosion, has excellent corrosion resistance in most chemical media. Now, with the advancement of 

technology and the application of new materials industries for increasing the degree of titanium 

valves as a variety of special circumstances and special fluid media delivery system essential 

products have been widely applied. However, different fields and industries fluid medium and 

environmental conditions vary, the titanium material of the valve performance and other requirements 

are different. Meanwhile, due to the requirements of the different components of performance 

titanium valves differences, different molding process as well as reduce the cost of some parts need 

to use alternative materials and other factors, selection as one of technical problems must be the 

primary consideration titanium medical grade titanium alloy‍ valve design manufacture, and by widespread concern and attention.