Interface characteristics and wear performance of ZTA_P@Ti+TiB₂ dual-scale particle reinforced iron matrix composites

High-chromium cast iron matrix composites reinforced with zirconia-toughened alumina ceramic particles (ZTA_P/Fe composites) benefit from the low cost of the ceramic particles and high strength/toughness of the iron matrix; and are advanced wear-resistant materials with great potential for industrial application. However, the poor wettability of ceramic particles with liquid iron may cause them to detach from the matrix during the wear process. This study investigated the interfacial characteristics, mechanical properties, and abrasive wear behaviour of iron-based composites reinforced with dual-scale particles (ZTA_P@Ti + TiB₂). The results demonstrated that the sintering process played a crucial role in the formation of the micrometer-scale TiB₂ phase inside the ZTA ceramic preform, which originated from the elemental Ti, B, Fe, and Al powders and ZTA particles. The optimal compressive strength (5.9 MPa) and porosity (35.3 %) were achieved after sintering at 1200 °C for 2 h. Subsequently, defect-free (ZTA + TiB₂)_P/Fe composites were fabricated using an infiltration casting method. The microstructure and phase composition of the composite interface layer were analysed using scanning electron microscopy and electron probe microanalysis. A mechanism for improving the wear performance of the composites under fixed-load conditions was investigated. The relative wear resistance of the (ZTA + TiB₂)_P/Fe composites was measured to be 2.69 times higher than that of a Cr15 sample. This study addressed the research gap in particle-scale investigations of ZTA/Fe composites.