SHS Compaction of TiC-Based Cermets Using Mechanically Activated Mixtures

This paper is concerned with obtaining metal-ceramic composite materials through the method of SHS compaction. The study investigates the influence of mechanical activation of metallic components in reactive mixtures based on the Ti + C + Cr + Ni system on the structure and properties of the resulting composites. Mechanical activation of the Ti, Cr, and Ni metallic powders was performed using two methods. In the first method, Cr and Ni powders were activated separately from the other components of the reactive mixtures using grinding media in a ball mill, after which they were mixed with Ti and carbon black powders. It was shown that the preliminary mechanical activation of the inert components reduces the combustion temperature and rate, which increases the average size of carbide grains. The second method involved a joint processing of Ti + Cr, Ti + Ni, and Ti + Cr + Ni powder mixtures in a ball mill, which were then mixed with carbon black. This method provided mechanical activation of titanium particles while minimizing the impact of grinding media on Cr and Ni powders. This led to an increase in the combustion rate and temperature, a decrease in the average size of carbide grains, and an improvement in the uniformity of the composite structure. A mechanism of interaction between the reagents (Ti + C) involving activated Cr and Ni particles in the combustion and structure formation zones is proposed. According to this mechanism, the mechanical activation of inert components leads to their direct participation in the reaction between titanium and carbon, which determines the reduction in combustion rate and temperature and affects the dispersion and uniformity of the structure of compact composites. The results were used to enhance the uniformity and refine the structure of the STIM-3B composite (synthetic hard tool material grade 3B).