The influence of vibration of cutter teeth on the surface roughness and tool life. In order to prevent the decline of machining accuracy and tool life, the selected machining center must be equipped with a spindle with excellent dynamic balance performance, and the selected boring tool must also have high dynamic balance characteristics. Especially for the cutter tooth part of boring tools, the geometry, tool material and clamping mode suitable for high-speed cutting should be selected. In order to improve the machining efficiency, the feed rate should be increased on the premise of obtaining the same surface roughness. However, the increase of feed rate should be enough, otherwise it will increase the cutting resistance, which is not conducive to improving the processing efficiency. The cutting edge should be set with negative chamfering less than 0.1 mm, which can effectively maintain the stability of tool life.
In addition to CNC cutting method for precision machining of holes, boring and reaming can also be used for high-precision machining of holes. With the high-speed spindle of machining center, boring tools can be used for high-speed and precision machining of holes. It is reported that the cutting speed can be increased to more than 1500m / min when the diameter of boring is about 40mm on aluminum alloy. This cutting speed can also be used when using CBN sintered body as cutting edge to process steel, cast iron and high hardness steel. It is predicted that the high speed of boring will be popularized rapidly in the future.
As for the tool material, it depends on the nature of the material being processed. For example, when machining steel below 40HRC, cermet tool can be selected. Under the high-speed cutting condition of V = 300m / min, good surface roughness and long tool life can be obtained. Coated cemented carbide tools are suitable for high-speed cutting of steels below 60HRC. The tool life is very stable, but the cutting speed is slightly lower than cermet tools.
Sintered tool is suitable for machining high hardness steel, cast iron and other materials. The cutting speed can reach more than 1000m / min, and the tool life is very stable. Proper chamfering should be carried out on the cutting edge of CBN cutter teeth in CNC machining, which is very beneficial to stable high-speed cutting and prolonging tool life. In ultra-high speed cutting of nonferrous metals and non-metallic materials such as aluminum alloy, diamond sintered body tool can be selected. This kind of cutting tool is stable and has a long service life. It should be noted that when using diamond tools, the blade belt must be chamfered, which is an important condition to ensure the stability of cutting.
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