Cutting ability of abrasive grains in the processing of billets of plastic materials

Abstract

When processing billets of plastic and adhesive-active materials, the loss of the cutting ability of the grinding wheel is mainly due to the adhesion of the workpiece material particles to the abrasive grains (AG). To develop recommendations aimed at reducing the intensity of adhesion, it is necessary to identify the relationship of the intensity of this process with the physical and mechanical properties of abrasive grains. The dependence for the calculation of the voltage at the contact area of the clip with the AG after the AG out of contact with the workpiece is obtained. Numerical simulation of local temperature when microreserve (scratching) samples of steel 3KH3M3F abrasive grains of various materials. According to the obtained dependences, the deformation of the excrescence and the stresses resulting from this deformation were calculated, and the ones acting on the connection of the 3KH3M3F steel excrescence with grains from materials having different coefficients of linear expansion. It is established that with the increase in the difference of the coefficients of linear expansion of the billet materials and AG, the stresses that contribute to the separation of the excrescence from the surface of AG increase, which allows to predict a lower intensity of sticking of the billet material to AG from such materials. It is established that with the increase in the difference of the coefficients of linear expansion of the billet materials and AG, the stresses that contribute to the separation of the excrescence from the surface of AG increase, which allows to predict a lower intensity of sticking of the billet material to AG from such materials. Experimental studies, during which micro-cutting of samples by single abrasive grains was carried out, showed that AG from elbor wear out and are salted to a lesser extent. Elbor has the maximum value of the coefficient of thermal conductivity among the tested materials and to a lesser extent wears out, so the local temperatures when cutting grains from Elbor are minimal. In addition, the difference between the linear expansion coefficients of the material excrescence and elbor has a maximum value. Therefore, at the site of contact AG from elbor with the adhesive there are stresses that contribute to the separation of the excrescence from this surface, which is the reason for the small value of the coefficient of salting AG from elbor. As a result, AG was ranked from various materials according to the criteria characterizing their wear and salting. Confirmed identified analytically the relationship between the intensity of brining of grain with a coefficient of linear expansion and thermal characteristics of the materials AG.