Machining can be roughly divided into turning, milling, and cutting with center teeth (drills, face milling of end mills, etc.). The cutting heat of these cutting operations also affects the blade tip. Turning is a kind of continuous cutting, cutting force without significant changes in cutting edge, cutting heat continuously acting on the cutting edge; milling is a kind of intermittent cutting, cutting force is intermittently acting on the cutting edge, vibration will occur when cutting, The heat affected by the cutting edge is alternating between heating during cutting and cooling during non-cutting. The total amount of heat received is less than that during turning.
The cutting heat during milling is an intermittent heating phenomenon. The cutting teeth are cooled when they are not cut, which will help the tool life longer. The physical and chemical research institute of Japan has conducted comparative tests on the tool life of turning and milling. The tool used for milling is a ball end mill and the turning tool is a general turning tool. Both are in the same material and cutting conditions (due to different cutting methods, cutting Depth, feed rate, cutting speed, etc. can only be roughly consistent) and the comparative test under the same environmental conditions, the results show that the milling process is more beneficial to extend the tool life.
When a cutting tool such as a drill with a center cutting edge (that is, a cutting speed = 0 m/min.) or a ball end mill is used for cutting, the tool life near the center cutting edge often appears to be low, but it is still stronger than during turning. When cutting hard-to-machine materials, the cutting edge is greatly affected by heat and often reduces the tool life. If the cutting method is milling, the tool life will be relatively longer. However, difficult-to-machine materials cannot be entirely milled from beginning to end, and there will always be times when turning or drilling is required in the middle. Therefore, corresponding technical measures should be taken for different cutting methods to improve the processing efficiency.