Change in the characteristics of the grinding wheel face during its redress life

Based on a comprehensive analysis of grinding operations, it was found that grinding wheels are the most unstable elements of the system. During grinding, the cutting surfaces are formed by the movement of the cutting edges of abrasive grains in the workpiece space. They form a microrelief on the workpiece surface. It was shown that the main parameter of the grinding process that has the most significant impact on the quality of cutting is the shape of the cutting edges. The shape of single surface scratches depends on the characteristics of the contact between the grinding wheel and the workpiece material, as well as the shape of abrasive grains on the grinding wheel face. Change of state of the grinding wheel face is determined by the number of cutting edges, their shape, and the distribution of cutting edges on the wheel face. We developed a methodology and conducted research to determine the empirical coefficients that define the influence of the working time of a dressed grinding wheel on the state variables of the working surface. We proposed analytical expressions for calculating the expected surface roughness, cutting force, etc. It was found that an increase in tool operation time leads to an increase in the width of the cutting edge and the radius of curvature at the top of the tool; and when it operates in the blunt mode, there are near-planar vertices. The experimental studies confirm the conclusion that the shape of the cutting edges changes most significantly when the tool operates in the blunt mode during its tool life. The research on the wear of single abrasive grains of the circle confirms the qualitative characteristics of wear. The calculated values of the curvature radius when compared to the experimental ones show quite a good coincidence.