Cutting is roughly divided into turning, milling and cutting based on Center teeth (end face cutting of drill bits and end mills, etc.), and the cutting heat of these cutting processes also has different effects on the tip. Turning is a continuous cutting, the cutting force borne by the tip has no obvious change, and the cutting heat acts on the cutting edge continuously; Milling is an intermittent cutting. The cutting force acts on the tip intermittently, and vibration will occur during cutting. The thermal effect on the tip is that the heating during cutting and the cooling during non cutting are carried out alternately, and the total heat is less than that during turning.
The cutting heat during milling is an intermittent heating phenomenon, and the cutter teeth are cooled when not cutting, which will be conducive to the extension of tool life. The Japanese Institute of physics and chemistry has made a comparative test on the tool life of turning and milling. The cutting tools used for milling are ball end mills and turning are general turning tools. The cutting comparative tests are carried out under the same processed materials and cutting conditions (due to different cutting methods, the cutting depth, feed rate, cutting speed, etc. can only be roughly the same) and the same environmental conditions. The results show that milling is more beneficial to extending the tool life.
When cutting with tools such as drills and ball end mills with central edges (i.e. parts with cutting speed =0m/min), the tool life near the central edge is often low, but it is still stronger than that during turning. When cutting difficult to machine materials, the cutting edge is greatly affected by heat, which often reduces the tool life. If the cutting method is milling, the tool life will be relatively long. However, difficult to machine materials cannot be milled all the time, and there will always be times when turning or drilling processing is required. Therefore, corresponding technical measures should be taken for different cutting methods to improve processing efficiency.
