The principle of titanium alloy and its Characteristics and shortcomings

The principle of titanium alloy TitaniumCN 
Titanium alloy is based on titanium to join other alloy elements.Titanium has two homogenous different crystal: under 882 ℃ to close the six-party alpha titanium structure, above 882 ℃ for body centered cubic beta titanium.
Alloying elements according to their influence on phase change temperature can be divided into three categories:
(1) a stable alpha, increase the temperature of the phase transition element for alpha stable elements, such as aluminum, carbon, oxygen and nitrogen.Including aluminum titanium alloy main alloy elements, it is to improve the alloy at room temperature and high temperature strength, reduce weight, increasing the elastic modulus have obvious effect.
(2) stable beta phase, to reduce the phase transition temperature elements for beta stable elements, and can be divided into two isomorphous and eutectoid type.
The application of titanium alloy products
The former are molybdenum, niobium, vanadium, etc.;The latter has a chromium, manganese, copper, iron, silicon, etc.
(3) the phase transition temperature impact elements to neutral elements, such as zirconium, tin.
Oxygen, nitrogen, carbon and hydrogen is the main impurity of titanium alloy.Oxygen and nitrogen in the alpha phase has larger solubility, to strengthen titanium alloy has a significant effect, but it is plastic.Usually prescribed titanium content of oxygen and nitrogen in under 0.15 ~ 0.2% and 0.04 ~ 0.05% respectively.Hydrogen in the alpha phase solubility is small, dissolve excess hydrogen yield in titanium alloy hydride, alloy become fragile.Usually controlled under 0.015% hydrogen content in titanium alloys.The dissolution of hydrogen in titanium is reversible and can be removed using a vacuum annealing.
disadvantages.
Titanium and titanium alloy limitation is mainly in high temperature and chemical reactivity with other materials.The nature of the force of titanium alloy and conventional refining, melting and casting technology is different, and often causes the damage of mold;As a result, make the price of titanium alloy is very expensive.So they began to use mostly in aircraft construction, aircraft, and used in the oil and chemical industry and other high-tech industries.But because of the space science and technology developed, people's quality of life has increased, so the titanium alloy also gradually used to make consumer goods, for the benefit of life of life, only these prices are still on the high side, belongs to the high price of the product, it is unable to carry forward the Achilles' heel of the biggest titanium alloy.
The main characteristics
Titanium alloy main features;Industrial pure titanium: pure titanium more than chemical pure titanium content of impurities, so its strength and hardness is high, its mechanical properties and chemical properties similar to stainless steel, compared with the strength of pure titanium, titanium alloy is better than that of austenitic stainless steel in terms of oxidation resistance, but poor heat resistance, TA1, TA2 and TA3 higher content of impurities, mechanical strength, hardness, in turn, enhanced, but the plastic toughness decline in turn.