Mechanical, Tribological, and Thermal Properties of Hot‐Pressed Z r B 2 ‐ B 4 C Composite

The effect of addition of submicrometer‐sized B 4 C (5,10 and 15 wt%) on microstructure, phase composition, hardness, fracture toughness, scratch resistance, wear resistance, and thermal behavior of hot‐pressed Z r B 2 ‐ B 4 C composites is reported. Z r B 2 ‐ B 4 C (10 wt%) composite has V H 1 of 20.81 GP a and fracture toughness of 3.93 at 1 kgf, scratch resistance coefficient of 0.40, wear resistance coefficient of 0.01, and ware rate of 0.49 × 10 −3 mm 3 /Nm at 10N. Crack deflection by homogeneously dispersed submicrometer‐sized B 4 C in Z r B 2 matrix can improve the mechanical and tribological properties. Thermal conductivity of Z r B 2 ‐ B 4 C composites varied from 70.13 to 45.30 W/m K between 100°C and 1000°C which is encouraging for making ultra‐high temperature ceramics ( UHTC ) component.