Volume Distribution of Reinforce Particles in a Metal Matrix

Abstract

The authors studied the volume distribution of particles from ultrafine powders of natural diamond, used as a hardener for a post of diamond tools made on a metal basis by powder metallurgy methods. In [15-17], the authors determined that the addition of ultrafine natural diamond powders to the melt of tin bronze in an amount of 2-3% by weight has a positive effect on the physicomechanical and operational properties of the metal post. It was also determined that the hardening mechanism of the materials under study depends on the nature of the distribution of the hardener particles in the bulk of the matrix. In accordance with previous studies, the authors set the aim - to determine the distribution nature of reinforcing phase particles in the volume of the metal matrix. The studies were carried out using optical metallography, SEM microscopy and Raman spectroscopy. It was established that the particles of the hardener in the volume of the matrix are distributed evenly along the phase boundaries and in the body of the grains and reduce the number of pores formed during sintering compared with the original samples. With the established nature of the distribution of particles, a grain-boundary hardening mechanism is realized, in which dislocations are inhibited by grain boundaries, which are an insurmountable obstacle for them. It is also established that a part of the particles settle directly inside the grains of the material and is distributed throughout the volume uniformly contributing to the dispersion hardening mechanism.