The processing difficulty of titanium alloy parts is very high. The comprehensive process of titanium and titanium alloys is very different 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 alloy is a difficult to process metal.

(1) Due to the instability of its chemical composition. Under thermal deformation, TC4 titanium alloy will react chemically with oxygen and nitrogen, and even with some oxygen-containing gases. The reaction will produce oxide skin attached to the surface of the workpiece. If the temperature is higher and reaches above 900 ℃, the oxide skin attached to the surface of the workpiece will form scales, which is likely to penetrate and disperse oxygen and nitrogen elements into the metal, ultimately forming an external suction layer. High hardness and low plasticity are the characteristics of this suction layer

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

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