Process analysis of drilling and tapping of bright parts

The reason why titanium alloys are difficult to process is the comprehensive effect between the mechanical, chemical and physical properties of the titanium alloy itself. Due to the low thermal conductivity of titanium alloys, heat dissipation is slow, which is not conducive to heat balance, especially during the drilling process. The heat dissipation and cooling effects are very poor. High temperatures are formed in the cutting zone and the rebound after processing is large. Therefore, when the drill tip contacts the workpiece , The contact area between the tool tip and the workpiece increases, which increases the axial force on the tool tip, and the tool tip is easy to cause wear and damage. After the drill bit enters the workpiece, due to the radial elasticity tightening and poor thermal conductivity of the titanium alloy, the drill bit is subject to large radial and axial forces. Ordinary drill bits are prone to processing and aggravated by difficult wear. Titanium alloys have high chemical activity and are exposed to high temperature and high pressure. Machining, it reacts with the tool material to form an alloy that is deposited and diffused, causing sticking of the tool, chipping is not easy to remove, often resulting in bit bite, twisting of the bit, etc. Internal thread tapping on titanium alloy material is titanium alloy cutting The most difficult process in processing, especially for small hole thread processing, which is more difficult and cannot be separated from tap tapping. The main reason is that titanium alloy has low thermal conductivity. During the tapping process, the cutting temperature is high and the chips are sticky. The phenomenon is not easy to eliminate, the cutting fluid is not easy to reach the cutting area, etc.; the processed surface is prone to stress concentration and the formation of a hard and brittle layer, and the surface quality of the processed thread is poor. In addition, the rebound of the titanium alloy after processing is large, the hole wall squeezes the tap, and even The tooth-shaped bread stays, the tap cannot be rotated, and the tap is easy to break.