The specific strength of titanium alloy products is very high among metal structural materials. Its strength is equivalent to that of steel, but its weight is only 57% of steel. In addition, titanium alloy has the characteristics of small specific gravity, high thermal strength, good thermal stability and corrosion resistance, but titanium alloy materials are difficult to cut and have low processing efficiency. Therefore, how to overcome the difficulty and low efficiency of titanium alloy processing has always been an urgent problem to be solved.
Reasons for difficult titanium alloy processing
The thermal conductivity of titanium alloy is small, so the cutting temperature is very high when processing titanium alloy. Under the same conditions, the cutting temperature of processing TC4 is more than twice that of 45 steel, and the heat generated during processing is difficult to release through the workpiece; The specific heat of the alloy is small, and the local temperature rises quickly during processing. Therefore, the temperature of the tool is very high, the tip of the tool wears sharply, and the service life is reduced.
The low modulus of elasticity of titanium alloy makes the machined surface easy to spring back, especially the processing spring back of thin-walled parts is more serious, which is easy to cause strong friction between the flank face and the machined surface, thereby wearing tools and chipping.
Titanium alloys are very chemically active and easily interact with oxygen, hydrogen, and nitrogen at high temperatures, increasing their strength and decreasing plasticity. The oxygen-rich layer formed during heating and forging makes machining difficult.