Characterization and mechanical modeling of the abrasion properties of sintered tools with embedded hard particles

A wide variety of applications, ranging from rough cutting of stone and concrete to ultra-precision machining of ceramics for electronic components, are commonly performed with the so-called super-abrasive tools. The working part of such tools is made of hard particles, typically diamonds or cubic boron nitride crystals, embedded in a resin or sintered metal matrix. The performance of the tool is influenced by many technological aspects, but basically depends on the abrasion property of the hard particles-matrix system. In the present paper, a mechanical approach is followed in order to link the performance of a tool to some relevant design parameters, i.e. hard particle content and diameter. The model is based both on theoretical and experimental evidences. An experimental technique is described for the tool characterization, based on a coupled optical and laser-scanner acquisition of the tool working-surface. Moreover, the tool design parameters are put into play through a stereological model. The numerical strategy of the presented model is justified by a preliminary study of the contact stress distribution over the contact area. Different useful parameters (i.e. distribution of contact stresses, number of active particles, etc.) are obtained from the numerical simulation of abrasion, although the performance of the tool is primarily evaluated from the estimated removed volume.