Titanium Alloy- Principle
Titanium alloy- Principle
Application of the product titanium alloy
Titanium Two allomorphs: The following 882 ℃ for the hcp α titanium, 882 ℃ above the body-centered cubic β titanium.
Alloying elements according to their influence on the phase transition temperature can be divided into three categories:
① stable α phase, increase the phase transition temperature of the element α stabilizing element, aluminum, carbon, oxygen and nitrogen. In which aluminum is the main alloying elements titanium, improve its normal temperature and high temperature strength of the alloy, reduce the proportion of increased elastic modulus have a demonstrable effect.
② stable β phase, lower phase transition temperature of the element β stabilizing element, can be divided into the same crystal type and eutectoid two kinds. The former molybdenum, niobium, vanadium; the latter are chromium, manganese, copper, iron, silicon and the like.
③ small element of the phase transition temperature for the neutral elements, zirconium and tin.
Oxygen, nitrogen, carbon and hydrogen are the main titanium impurities. Oxygen and nitrogen in the α phase has a greater solubility of titanium have a significant strengthening effect, but the plastic drop. Usually it provides the titanium content of oxygen and nitrogen 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 hydrogen will produce excess hydride, the alloy becomes brittle. Usually titanium hydrogen content control in 0.015%. Hydrogen dissolved in titanium is reversible, can be removed by vacuum annealing.