Preparation and Mechanical Properties of (TiCrZrNb)C4-SiC Multiphase High-Entropy Ceramics

Five carbide powders, TiC, Cr3C2, ZrC, NbC and SiC, were selected as raw materials and mixed by dry or wet milling. Then (TiCrZrNb)C4-SiC multiphase ceramics were successfully prepared by spark plasma sintering (SPS) at 1900 °C, using D-HECs-1900 (dry milling method) and W-HECs-1900 (wet milling method), respectively. In this study, the effects of the ball milling method on the microstructure and mechanical properties of the multiphase high-entropy ceramics were systematically investigated. Compared to D-HECs-1900, W-HECs-1900 has a more uniform elemental distribution and smaller grain size, with an average grain size of 1.8 μm, a higher Vickers hardness HV0.1= 2178.41 kg/mm2and a higher fracture toughness of KIC= 4.42 MPa·m1/2. W-HECs-1900 also shows better wear resistance with a wear rate 1.01 × 10−8mm3·N−1·m−1. The oxide friction layer formed during friction is beneficial for reducing frictional wear, making W-HECs-1900 a potential wear-resistant material.