Wear Response of Carbide-Reinforced 1.75 mol% Y2O3-Stabilized ZrO2 Composites Under Dry Sliding Conditions

This study investigates the mechanical and tribological behavior of three composites with a ZrO2 matrix stabilized with 1.75 mol% Y2O3 and containing 1 wt.% Al2O3, reinforced with TiC (A), TiC + ZrC (B), and TiC + WC + Mo2C (C). The matrix powder was synthesized by chemical coprecipitation, and the composites were consolidated by spark plasma sintering at 1350 °C. Dry reciprocating sliding tests against 100Cr6 steel were performed at 10 and 25 N. Composite A exhibited the highest HV10 hardness (1268), while the indentation fracture toughness values were similar (6.41–6.57 MPa·m1/2). Wear resistance did not follow the hardness ranking. At 25 N, composite A exhibited surface fragmentation and a specific wear rate of 2.52 × 10−6 mm3·N−1·m−1, while composite B showed extensive and heterogeneous transfer of steel-derived material. Composite C exhibited the lowest coefficient of friction and specific wear rate, reaching 0.392 and 7.04 × 10−8 mm3·N−1·m−1, respectively, at 25 N. EDS mapping revealed an area-integrated Fe content of 0.7 at.% for C, compared with 7.2 at.% for A and B. The superior wear resistance of C was associated with substantially lower steel-derived material transfer and a relatively smooth wear-track surface rather than with the highest bulk hardness.