The choice of cutting tools is one of the important contents of CNC machining process, which not only affects the machining efficiency of the machine tool, but also directly affects the machining quality of the parts. CNC tools are one of the prerequisites for improving machining efficiency. Its selection depends on the geometry of the processed parts, material conditions, fixtures and the rigidity of the selected tools of the machine tool. The following aspects should be considered:
(1) Choose the tool according to the cutting performance of the part material. Such as turning or milling high-strength steel, titanium alloy, stainless steel parts, it is recommended to choose indexable carbide tools with good wear resistance.
(2) Select the tool according to the processing stage of the part. That is to say, the rough machining stage is mainly to remove the margin, and the tool with better rigidity and lower precision should be selected. The semi-finishing and finishing stages are mainly to ensure the machining accuracy and product quality of the parts, and the high durability and high precision should be selected. For high cutting tools, the precision of the cutting tool used in the roughing stage is the lowest, and the cutting tool used in the finishing stage has the highest precision. If you choose the same tool for roughing and finishing, it is recommended to use the tool eliminated from the finishing process during roughing, because most of the tool wear out of the finishing process is slight wear of the blade, and the coating is worn and polished. Continued use will affect CNC machining. The quality of processing, but the impact on rough processing is small.
(3) Select the tool and geometric parameters according to the characteristics of the processing area. When the part structure allows, the tool with large diameter and small ratio of length to diameter should be selected; the end edge of the over-center milling cutter for cutting thin-walled and ultra-thin-walled parts should have sufficient centripetal angle to reduce the cutting of the tool and the cutting part force. When processing softer material parts such as aluminum and copper, you should choose an end mill with a slightly larger rake angle, and the number of teeth should not exceed 4 teeth.