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Application of CVD Diamond Coated Tools in 3D Glass, Ceramics and High-end Materials

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Update time : 2018-06-15 16:28:09

The choice of the thickness of the diamond coating is not "the thicker the better" and the wear resistance is improved. The quality of the diamond coating is greater than the thickness. With the full explosion of the 3D glass market, the excellent performance of graphite materials in the application of 3D glass bending tools has been unanimously recognized by the industry. Due to the high abrasiveness and toughness of graphite materials, the processing environment of graphite molds is very strict. In order to ensure the graphite mold has good precision, smoothness, stability, in addition to the need to be quiet, the body's own suction capacity, the graphite processing tool has become the most important part of the processing link, select the tool suitable for high-speed machining, need to To improve durability, reliability, and safety, comprehensive consideration is given to the matching of tool bases with coating materials and tool and workpiece materials.
Diamond cnc insert,CBN insert
After continuous testing and verification of various tool materials, the service life of CVD diamond-coated tools is 8 to 10 times that of cemented carbide. The allowable cutting speed of CVD diamond-coated tools is 2 to 3 times higher than that of cemented carbide tools. Sharp edge and good consistency, low friction factor, high-speed and high-precision machining of thin-walled graphite molds can be achieved at high rotation speeds and low feed rates. At the same time, the service life of CVD diamond-coated tools is received by various graphite processing companies in many tool materials. Favored!
Chemical Vapor Deposition (abbreviated as CVD) diamond coating has many excellent properties such as high hardness, high thermal conductivity, low friction and low expansion coefficient close to that of natural diamond. When processing brittle materials such as graphite and carbon fiber composite materials, It has become a surface coating for cutting tools and has demonstrated excellent performance in terms of improved tool life and machining quality.
According to the grain size, CVD diamond coating can be divided into micro-diamond coating and nano-diamond coating. The grain size of the micro-diamond coating is usually between 500 nm and several micrometers. It is formed by the competitive growth of diamond grains grown in a column shape. It has excellent properties such as high hardness and good surface wear resistance, which can significantly reduce the tool wear rate. Improve tool life. However, the surface of micro-diamond coating is rough (Ra value is usually several hundred nanometers). The coating toughness and crack growth resistance are poor. The surface cracks easily spread along the grain boundary region to cause the coating to fall off, so that the tool surface is not reached. Before the blunt standard, the coating has come off. The nano-diamond coating consists of cluster-like nano-sized diamond grains. The grain size is usually below 100 nm, and the surface is smooth (Ra value is less than 100 nm), which can significantly reduce the friction during the cutting process. Reduce cutting force and cutting heat and increase tool life. The nano-diamond coating has good resistance to crack propagation. However, compared with micro-diamond, it has a relatively low bonding strength with the substrate, and it is prone to abnormal failures such as peeling of the coating during processing.
The main basis for the selection of diamond-coated tools is the properties of the workpiece materials and the processing quality requirements. For the EDM graphite mold processing, the essence of the milling process is similar to the “grinding” process. At this time, the “micro edge” of the tool surface is required to be large and wear-resistant, and the larger diamond micro-diamond coating should be selected. For molds used for ceramic processing, high surface finishes are required and nanodiamond coatings should be used during the finishing stage. In the processing of aluminum alloys, the severity of the “sticking knife” phenomenon is higher than the tool wear. At this time, the wear resistance of the tool is relatively low, and a nano-diamond coating with a low friction coefficient should be selected. For carbon fiber composite materials, micro-/nano composite diamond coatings should be used because of the strong abrasive properties of fiber materials, which require that the tool have good wear resistance, but also reduce the cutting force and cutting heat during processing. In particular, the choice of the thickness of the diamond coating is not "the thicker the better" and the wear resistance is improved. The quality of the diamond coating is greater than the thickness.