Compared with other metal materials,
titanium alloy has the following advantages:
(1) than the strength (tensile strength/density) high (see figure), tensile strength can reach 100 ~ 140kgf/mm2, and the density is only 60% of steel.
(2) good medium temperature strength, the use of temperature than aluminum alloy several hundred degrees higher, in the medium temperature can still maintain the required strength, can work in the temperature of 450 ~ 500℃ for a long time.
(3) corrosion resistance, in the atmosphere of titanium surface immediately formed a uniform dense oxide film, has the ability to resist a variety of medium erosion. Generally, titanium has good corrosion resistance in oxidation and neutral medium, and it has better corrosion resistance in seawater, wet chlorine gas and chloride solution. But in the solution of reducing medium, such as hydrochloric acid, the corrosion resistance of titanium is poor.
(4) low temperature performance, very low gap elements of titanium alloy, such as TA7, at -253℃ can maintain a certain plasticity.
(5) low elastic modulus, small thermal conductivity, no ferromagnetism.
(6) High hardness.
(7) Poor ramming and good thermo plasticity.
Different phase composition and microstructure of titanium alloy can be obtained by adjusting heat treatment process. It is generally believed that fine equiaxial microstructure has good plasticity, thermal stability and fatigue strength. Acicular structure has high endurance strength, creep strength and fracture toughness. Isometric and acicular mixed tissues have better comprehensive properties.
