The characteristics, judgment method and influence of grinding wheel wear

　　Grinding wheel is commonly used in machining, and its wear degree has an important impact on machining quality and efficiency. Therefore, it is very important to understand its wear characteristics, judgment methods and influence.

　　First, the characteristics of wear

　　Wear is mainly manifested in the following aspects.

　　1, abrasive failure: grinding wheel wear generally begins with abrasive failure. The performance of abrasive failure is that the pitting on the abrasive surface becomes larger, the density becomes smaller, and the abrasive particles break or break. When the abrasive fails, the abrasive density on the wheel surface is reduced, and the grinding force and cutting heat are concentrated around the failed abrasive particles, making them wear faster.

　　2, alloy matrix wear: after the abrasive failure, the alloy matrix of the grinding wheel begins to wear. As it rotates, the contact point between the abrasive and the object being machined changes constantly, and each particle of the grinding wheel is subjected to multiple pressures and frictions. These forces will gradually wear the surface of the alloy matrix and lose the original flatness.

　　3, burr formation: After wear, abrasive particles and alloy matrix surface will appear burrs, which will affect the machining surface finish and dimensional accuracy. If worn excessively, abrasive particles and burrs weaken the strength and stiffness of the structure, making it prone to cracking and breaking.

　　Second, wear judgment method

　　Correctly judging the wear condition is the key to ensure the quality and efficiency of machining. Here are some common ways to judge.

　　1. Visual inspection method: After the grinding wheel is removed, the wear condition of the surface, side and edge of the grinding wheel is visually detected to determine whether the grinding wheel needs to be replaced. For example, whether the abrasive particles on the wheel surface are still complete, dense, centered, or have broken stars, pitting deformation and so on.

　　2, touch method: touch the surface and side with fingers, feel the smoothness and roughness. In general, if the surface has more burrs and uneven conditions, it may have been worn more obviously.

　　3, shoe shape method: it is installed on a special measuring equipment, according to the difference between the wheel contour and the standard shoe shape, to judge the degree of wear. If the wear is serious, the convex part of the wheel face and the upper edge part will be worn flat, and the outline will change.

　　Third, the impact of wear

　　The degree of grinding wheel wear is a key factor affecting machining quality and efficiency. Here are a few common effects.

　　1, processing accuracy decline: after wear, the size of abrasive particles and grinding efficiency will be reduced, making the dimensional accuracy of the processed material decline. At the same time, the generation of burrs will also affect the finish and surface quality of the processed material.

　　2, grinding force increase: abrasive particles and burrs on the surface of the grinding wheel will produce additional grinding force and cutting heat. This will not only accelerate wear, but also increase the wear of mechanical processing equipment, increase energy consumption, reduce processing efficiency and processing speed.

　　3, the increase of safety risks: when the wear is serious, it may lead to structural imbalance or rupture, resulting in mechanical processing equipment and personnel safety risks.

　　In order to ensure the quality and efficiency of machining, the wear of the grinding wheel should be checked regularly and replaced in time. At the same time, in the process of use, it is also necessary to pay attention to the scope of application, processing parameters and safety specifications, and strengthen the training and application of grinding technology.