Research status of resin-bonded diamond grinding wheel

Diamond grinding wheel is the most widely used processing tool in grinding technology. According to different kinds of bond, diamond grinding wheel can generally be divided into resin-bonded diamond grinding wheel, ceramic-bonded diamond grinding wheel and metal-bonded diamond grinding wheel. Resin-bonded diamond grinding wheels are mostly thermosetting resins, which have the advantages of low curing temperature and relatively simple preparation. They are mainly used for edge grinding, hole grinding, cylindrical grinding and surface grinding.

 

 

The resin-bonded diamond grinding wheel uses resin powder as the bonding material, adding filler materials, and making grinding tools with certain shape through hot pressing, hardening and machining. Recently, the binders used for resin-bonded diamond grinding wheels in China mainly include phenolic resin, epoxy resin and polyphthalimide, but their common problem is poor heat resistance. The grinding heat generated in the grinding process will lead to resin softening, decomposition and the reduction of adhesion to the abrasive. In the grinding process, the diamond abrasive is easy to fall off a lot without playing a good role, so the durability is very poor.

Phenolic resin (PF) is the first synthetic resin to realize industrialization in the world, and it is widely used in resin-bonded diamond grinding wheels. However, ordinary phenolic resin can be used stably as the resin bond of grinding wheels under 200 ° C. If it exceeds 200 ° C, its phenolic hydroxyl and methylene will be oxidized, affecting its heat resistance and oxidation resistance; The cured phenolic resin shows brittleness because only methylene is connected between aromatic cores.

Therefore, the traditional unmodified phenolic resin has high brittleness, poor toughness and insufficient heat resistance, which limits the application of resin-bonded diamond grinding wheel. Therefore, it is necessary to prepare high performance phenolic resin.

In recent years, domestic and foreign countries have attached great importance to the modification of phenolic resin and the strengthening and toughening of its composites. A series of phenolic resin varieties with excellent heat resistance and flame retardancy and high mechanical strength have been developed. For example, the molybdenum modified phenolic resin synthesized by Liu Xiaohong and others has a thermal decomposition temperature of 522 ° C, and the weight loss rate at 600 ° C is still 17.5%.

 

The friction material made of it has stable high temperature friction coefficient and good thermal recovery; Xiong Xuemei and others introduced polysulfone into the phenolic resin by melt blending, and used sisal fiber as the reinforcement of the modified phenolic resin, and made friction composites by pressure molding technology.

 

The results showed that the introduction of polysulfone could improve the heat resistance of the phenolic resin, and the friction properties of the composites were excellent; Zhou Yuankang and others added dispersed SiO2 nano-particles in the polymerization process of tung oil modified phenolic resin to prepare composite modified thermosetting phenolic resin, which was used in friction materials, and its thermal decay resistance and friction properties were significantly improved.