The processing difficulty of titanium alloy parts is very high. The comprehensive process of titanium and titanium alloys differs greatly from steel, aluminum alloys, and many heavy metals in terms of crystal structure, physical properties, and chemical properties. The following three factors determine that titanium alloys are a difficult metal to process.

(1) Due to its unstable chemical composition. TC4 titanium alloy will undergo chemical reactions with oxygen and nitrogen during hot deformation, as well as with some oxygen-containing gases. The reactions will produce an oxide scale attached to the surface of the workpiece. If the temperature is higher, above 900 ℃, the oxide scale attached to the surface of the workpiece will produce scales. In this way, oxygen and nitrogen elements are likely to infiltrate and disperse into the interior of the metal, forming an external suction layer. The characteristics of this suction layer are high hardness and low plasticity

(2) The manifestation of cementite in the metallographic structure belongs to a complex Fe-C compound, with a Vickers hardness of HV1100 and almost no impact toughness.

(3) Low thermal conductivity: If compared with other alloys such as aluminum alloy, the thermal conductivity of titanium alloy machined parts is only about 1/15 that of aluminum alloy and about 1/5 that of steel. The thermal conductivity and thermal conductivity of titanium alloy are much lower compared to aluminum alloy and steel, with only about 1/15 of aluminum alloy and about 2/7 of steel. This has a significant impact on the surface processing quality of some titanium alloy parts.