With the advancement of modern technology, various new composite materials and crystal materials are being used more and more widely, but these materials are difficult to process. For precision materials that are difficult to process, tools such as diamond grinding wheels are needed.
Pores are an important part of diamond grinding wheels, and their size and porosity have an important influence on the processing performance of grinding wheels. There are two main common pore-making methods: one method is to introduce pore-forming agents into the abrasive tool, such as refined naphthalene, phenol resin, carbon powder or ammonium salt, which decompose and produce gas at high temperature, leaving pores in the abrasive tool; the other method is to add hollow glass beads. Since the melting point of hollow glass beads is relatively high, they will not be decomposed during sintering, leaving closed and controllable pores in the grinding wheel segment. The first pore-making method is difficult to control the pore size, while the porosity and pore size of the second method are both controllable.
Several important functions of adding hollow glass beads:
1. Reduce density
The density of hollow glass beads is very low, usually between 0.2~0.6g/cm³, which makes it possible to significantly reduce the overall density of the material in the resin grinding wheel, thereby reducing the weight of the grinding wheel and facilitating operation and use.
2. Improve strength
Although the density of hollow glass beads is low, their compressive strength is high, which makes the grinding wheel less likely to break when subjected to external forces, improving the durability and service life of the grinding wheel.
3. Improve processing performance
Hollow glass beads have high dispersibility and good fluidity, which can reduce the viscosity of the resin, reduce the deformation and warping of the grinding wheel during processing, and ensure the dimensional stability of the product.
4. Improve flame retardant properties
The hollow glass beads are mainly nitrogen, carbon dioxide and other gases, which can be released at high temperatures, play a flame retardant role, and improve the safety of the grinding wheel.
