PTA clad (Cr,Fe)7C3/γ-Fe in situ ceramal composite coating

A wear-resistant (Cr, Fe)₇C₃/γ-Fe in situ ceramal composite coating was fabricated on the substrate of 0.45wt%C carbon steel by a plasma-transferred arc cladding process using the Fe-Cr-C elemental powder blends. The microstructure, microhardness, and dry-sliding wear resistance of the coating were evaluated. The results indicate that the microstructure of the coating, which was composed of (Cr, Fe)₇C₃ primary phase uniformly distributed in the γ-Fe, and the (Cr, Fe)₇C₃ eutectic matrix was metallurgically bonded to the 0.45wt%C carbon steel substrate. From substrate to coating, the microstructure of the coating exhibited an evident epitaxial growth character. The coating, indehiscent and tack-free, had high hardness and appropriate gradient. It had excellent wear resistance under the dry sliding wear test condition.