Processing features PCD&PCBN tool grinding machine
The 2-axis PCD&PCBN tool grinding machine is made of specially treated diamond and a small amount of binder sintered at high temperature and high pressure. The disorderly arrangement of diamond grains gives the PCD a uniform, extremely high hardness and wear resistance. The grinding of PCD and PCBN tools is mainly the result of a combination of mechanical and thermochemical effects. The result of the mixing of the two causes the PCD material to remove. Its grinding processing features are mainly.
1. The grinding force is very large
Diamond is the hardest material among the known minerals. The wear amount of the paired metal and non-metal materials is only 1/50~1/800 of the hard alloy. The hardness (HV) of the PCD is 80-120KN/mm2. Second only to single-crystal diamond, much higher than cemented carbide. When grinding PCD with a diamond grinding wheel, the initial cutting strength is very high, about 10 times higher than that of cemented carbide (0.4MPa). The specific grinding energy can reach 1.2×104～1.4×105J/mm3. Therefore, the grinding force is much higher. For grinding cemented carbide.
2. The grinding ratio is very small
Due to the high hardness and wear resistance of PCD (relative wear resistance is 16 to 199 times that of cemented carbide). The grinding ratio is only 0.005 to 0.033 when grinding PCD, which is about 1/1000 of cemented carbide. 1/100000. Grinding efficiency is only 0.4 to 4.8 mm3/min. Therefore, in order to ensure the cutting edge quality and removal amount of the cutting tool, the grinding time is long and the processing efficiency is low. In addition, when the hardness, content, and particle size of PCD are different, the grinding time is also very different.
The grinding efficiency of PCD&PCBN tool grinding machine
At present, with the rapid development of technology and market, has widely used. Demina summarized the market's high requirements for grinding efficiency in PCD and PCBN tool grinder equipment, mainly as follows.
1. The proportion of the indexable insert grinding is increased, requiring special equipment, simple structure, and strong rigidity. With the deepening of the division of labor, more than 80% of customers use this equipment to mass-produce the same type of tool. Namely PCNB, PCD or alloy indexable inserts, welding turning tools, etc. For a single requirement, the machine structure can simplify and the rigidity of the equipment is greatly enhanced. This not only reduces equipment costs but also lays a solid foundation for efficient production.
2. The main part of the auxiliary time - the tooling time requirement is greatly shortened. The arc of the insert is formed by the rotation of the table. Adjusting the center of the arc of the tool to coincide with the axis of rotation of the table is a prerequisite for grinding. And the “knife action” runs through the entire process of tool grinding and is repeated. This is the fundamental reason why traditional machine tools can't get rid of manual operations.
3.2-axis PCD&PCBN tool grinding machine requires easy and reliable operation and does not rely on the operator's manual skills. In order to grind natural diamond tools, the traditional machine tools introduce the "flexible feed" and "constant pressure grinding" processes. Which has the effect of "knife" protection for the highly brittle natural diamond knives. Conventional equipment uses a cylinder feed to achieve this effect, which greatly sacrifices the grinding efficiency of PCD and PCNB tools. In addition, due to the lack of precision in mechanical manufacturing. This machine tool is very unstable and requires a lot of manual skills to exert its strengths.
