Mechanical and tribological properties of NiCr-Al2O3 composites at elevated temperatures

The effect of Al2O3 content on the mechanical and tribological properties of Ni-Cr alloy was investigated from room temperature to 1000 °C. The results indicated that NiCr-40 wt% Al2O3 composite exhibited good wear resistance and its compressive strength remained 540 MPa even at 1000 °C. The values obtained for flexural strength and fracture toughness at room temperature were 771 MPa, 15.2 MPa m1/2, respectively. Between 800 °C and 1000 °C, the adhesive and plastic oxide layer on the worn surface of the composite was claimed to be responsible for low friction coefficient and wear rate.