Metal base CBN grinding wheel and manufacturing method thereof

Abstract

The invention discloses a metal base CBN grinding wheel and a manufacturing method thereof. The grinding wheel comprises a steel core and an abrasive ring; the abrasive ring is prepared by the following components in percentage by mass: 30-65% of CBN abrasive, 30-60% of metal bonding agent, and 5-15% of auxiliary bonding agent; and the metal bonding agent comprises the following components in percentage by mass: 50-60% of Cu powder, 30-45% of Sn powder, and 5-10% of Ti powder. The manufacturing method comprises the following steps: all the raw materials of the abrasive rings are uniformly mixed in proportion, and then, are uniformly mixed with the auxiliary bonding agent to dry as dried mixtures; the mixtures before drying are 90-95%; and the mixtures are sintered at corresponding temperature and time after screening and pressure molding, are cooled to discharge from a furnace, and are bonded with steel cores to prepare the metal base CBN grinding wheel. The grinding wheel is excellentin heat conductivity, and effectively enlarges the space for accommodating falling grains; the grinding wheel is high in grinding efficiency, low in grinding temperature, low in power loss, excellentin machining precision and long in service life; the method is short in sintering time; and the manufactured grinding wheel is sharp in grinding and high in grinding precision, and achieves self-sharpness.

Description

technical field [0001] The invention relates to the field of superhard abrasives, in particular to a metal-based CBN grinding wheel and a manufacturing method thereof. Background technique [0002] With the development of modern machining in the direction of high precision, high speed, hard machining, dry machining (no coolant) and cost reduction, quite high requirements are put forward for the performance of abrasive tools. Traditional silicon carbide and corundum ordinary abrasive molds can no longer fully meet the current high-speed, high-efficiency, and high-precision grinding requirements. Therefore, it is an inevitable development to develop various superhard grinding materials with excellent wear resistance and stable processing for a long time trend. Currently commonly used superhard grinding materials include cubic boron nitride (CBN) and diamond abrasives. Although the hardness of cubic boron nitride abrasive is lower than that of diamond, it is still much higher...

AI Technical Summary

Problems solved by technology

Traditional superhard abrasives (grinding wheels) are mostly manufactured by resin, ceramics, metal bond sintering and electroplating. The problem is that single crystal particles are only mechanically embedded in the bond and electroplating layer, and bond and Weak force between plating layers

Specifically, although the resin bond is relatively easy to process and repair, it has poor heat resistance, low bonding strength, serious abrasive shedding, and seriously affects efficiency; the vitrified bond is relatively easy to repair and has a high service temperature, but it is brittle and impact toughness. Poor fatigue, prone to brittle cracking, difficult to use in high-speed machining

Although metal bond sintering has strong heat resistance, chemical metallurgical bonding cannot occur between the bond and the abrasive grains, so the abrasive grains are only mechanically embedded in the bond with limited holding power; abrasive grains in metal electroplating are only mechanically embedded

Therefore, it is easy to cause the overall failure of the grinding wheel due to the particle shedding of the abrasive and the peeling off of the coating in flakes. This situation is especially obvious when the more difficult-to-process materials are efficiently ground; in addition, the coating is thick, the exposure height of the abrasive is low, and the chip space is small. , it is easy to fail due to the adhesion and clogging of chips during grinding