In the machining process of double-sided grinder, because the main function of abrasive particles is cutting, scraping and sliding, most of the abrasive particles are cut off, which makes the surface of the workpiece have high temperature in high-speed grinding. Under the action of higher temperature, the metallographic structure of the workpiece surface will change greatly, which will change the surface hardness of the workpiece and ultimately affect the performance of the workpiece.
At the same time, due to the different colors of the oxide film on the workpiece surface, the nature of grinding burn is the change of the material structure on the workpiece surface, mainly because the temperature of the treatment area is high. When the workpiece surface reaches a certain temperature, it is easy to burn.
In order to observe the combustion process of the workpiece surface, it is necessary to measure the average temperature of the workpiece surface at different stages. This test plays a very important role in solving the problems of combustion control and prediction in production. Facts have proved that grinding burn is a slowly changing process. In the plane grinder and polishing machine, the temperature will change, and the processing temperature will be completed in a short time. It may rise. It should be noted that the temperature here will change immediately. In essence, it is reflected in the step change of temperature on both sides, and the two are the same. If only the temperature change at this point is reflected, there are some problems in determining the burn change.
When the surface temperature of the workpiece increases gradually from low to high, and the temperature reaches or exceeds the combustion temperature of the workpiece material, the surface burn of the workpiece begins to appear.
In the process of double-sided grinder, if the grinding liquid is not used for cooling, the hardness of the workpiece surface layer will decrease sharply and the hardness of the workpiece surface layer will be annealed. Under the condition of rapid cooling with polishing liquid, the surface of the workpiece will be quenched and burned during grinding. If the surface temperature of the workpiece exceeds a certain range, rapid burning will occur.
The main cause of burn is high grinding temperature. Burns are mainly related to temperature. Due to many factors affecting the workpiece temperature, burns are affected to a certain extent. If the workpiece with poor combustion performance is easier to burn during combustion, the burn and grinding wheel will also be affected. If the hardness of the grinding wheel is high, the self sharpening performance is poor and burns will occur. Therefore, soft grinding wheel needs to be used to reduce burns. If coarse sand wheel is used, it is not easy to burn. If we want to improve the heating time and heat dissipation conditions, it will have a certain impact on severe burns. After the slurry is fully cooled, it is very beneficial to prevent burns and cracks.