Alloying element
titanium has two homogeneous heterocrystals: titanium with dense hexagonal structure below 882℃, titanium with body centered cubic structure above 882℃.According to their influence on phase transition temperature, alloying elements can be divided into three categories: stable phase and stable element, including aluminum, carbon, oxygen and nitrogen. Aluminum is the main alloying element of titanium alloy, which has obvious effect on improving the strength of alloy at room temperature and high temperature, reducing specific gravity and increasing elastic modulus. The stable element and the stable element can be divided into two types: isocrystalline and eutectoid. The former has molybdenum, niobium, vanadium and so on; The latter has chromium, manganese, copper, iron, silicon and so on. The elements with little influence on phase transition temperature are neutral, such as zirconium and tin.
