Microstructure, mechanical properties and wear behavior of (Ti,V)C/TiC reinforced Fe-based composite materials in-situ fabricated by SPS

To address the problems of relatively low densification and poor process controllability in ceramic particle-reinforced iron-based composites prepared by conventional casting method, (Ti,V)C/TiC carbide reinforced high-chromium iron was in situ synthesized via spark plasma sintering (SPS) in this work. The microstructure, mechanical properties and wear behavior of the composites were systematically investigated. By optimizing sintering parameters (1050℃×30 min), high-density composites with strong interfacial bonding were successfully fabricated. The results show that (Ti, V)C particles are spherical and uniformly dispersed, accompanied by a Cr-enriched M₇C₃-type carbide transition layer at the interface. High-density dislocations and favorable crystallographic matching are present among the reinforcing phases. The ceramic particle reinforced zone exhibits a hardness of 1573.5 HV, with elastic moduli of TiC (443.13 GPa) and (Ti,V)C (396.01 GPa) significantly exceeding that of the matrix phase (244.62 GPa). Three-body abrasive wear tests indicate that the composites possess superior wear resistance, with only one-third the volume loss of pure high-chromium iron. This improvement can be attributed to the "shadow effect" of (Ti,V)C/TiC reinforcements and the suppression of crack propagation due to their high elastic modulus. The dominant wear mechanism is characterized by shallow ploughing grooves. This work can provide a theoretical and practical reference for fabricating high-hardness and wear-resistant Fe-based composites via SPS.