Mathematic Model of the Blunting Area of an Abrasive Grain in Grinding Processes, with Account of Different Wear Mechanisms

Abstract

The intensity and the degree of blunting are the main factors which define the working capacity of a grinding wheel. When we consider the discrete contact of a grinding wheel with a work piece, the size of the blunting area can be such a factor. The article presents a mathematic model to calculate the blunting area of an abrasive grain whereby the main mechanisms of its wear such as mechanical and physicochemical phenomena are taken into account. The mechanical wear is studied from the standpoint of the kinetic theory of strength, a durability parameter for the abrasive grain is determined; the physicochemical wear is studied from the mass transfer theory, and coefficients of chemical affinity with the abrasive material are experimentally defined for the assortment of work piece materials. As mechanical and physicochemical wear of abrasive grain depend on the initial size of the blunting area, the suggested mathematic model is the first to consider nonlinear back-coupling, taking into account the size of the blunting area. The developed mathematic model is a multiple-factor one, which will allow to predict the worn area of the abrasive wheel for, and under different technological conditions.