Structure formation and characteristics of chromium carbide–iron–titanium cermets

Structure formation and properties of chromium carbide-based cermets with iron-titanium binder were investigated. Chromium carbide (50-70 wt%), Fe, and Ti (Fe : Ti ratio 4 : 1 as the binder phase) powders were milled in an attritor and a ball mill, compacted, and sintered at different temperatures and for different periods in vacuum. The microstructure, phase formation, and the composition of cermets were studied using XRD and EDS analysis and SEM. The results show that during the sintering of the Cr sub( 3)C sub( 2)-Fe-Ti composite at temperatures above 1000 degree C, diffusion of chromium and carbon into the ferritic matrix and Cr sub( 3)C sub( 2) recrystallization into the chromium ferrous dicarbide (Cr,Fe) sub( 23)C sub( 6) and the formation of chromium solid solution in the iron matrix (Fe(Cr) take place. Titanium participates actively in the interaction process, which leads to the formation of TiC carbides even at 1200 degree C. The mechanical properties (hardness, fracture toughness) and corrosion resistance in salt water were studied. Cermets sintered at lower temperature during a longer period demonstrated the best complex of mechanical properties.