Briefly Analyze The Precautions For Precision Machining Of Different Materials

In machining enterprises, machinable materials include not only aluminum alloy, magnesium alloy, magnesium-lithium alloy, low carbon steel, copper, stainless steel and other metal materials, but also non-metallic materials, such as ABS, PC, POM, PEEK, PP, acrylic (PMMA), nylon, Teflon, PPS, nylon + glass fiber and so on.

The cutting performance of metal materials is different from that of general non-metallic materials, therefore, different precision machining methods must be used, which includes the selection of tools, fixtures and cutting fluids and chip treatment, in addition, the generation and accumulation of cutting heat is a very serious problem, which can cause deformation and melting of non-metallic materials. This heat is transferred to the tool, which burns the cutting edge and reduces the tool's life.

In terms of material processability, non-metallic materials can be divided into three main categories: one is soft (low hardness) thermoplastics, including nylon, polytetrafluoroethylene (Teflon), acrylic and polystyrene. The second category is harder thermoset plastics, such as epoxy resins and phenolics. The third category is materials with abrasive components, such as carbon and graphite products and glass fiber epoxy resins.

Tungsten carbide tools or high-speed steel tools are suitable for the processing of non-metallic precision mechanical parts composed of wear materials such as glass fiber epoxy resin and graphite products, and the common standard tools for processing steel and cast iron are selected, and the helix angle of the tool should be less than 30 degrees for milling cutters and twist drills. Precision machining of non-metallic materials, cutting fluid is used for cooling rather than lubrication, phenolic, thermosetting plastics, carbon and graphite and other products are porous structures with water permeability, if the cutting absorber penetrates into the material, it will damage the precision mechanical parts, therefore, when cutting and processing these materials, air jets can be used as coolant.