Sliding wear and fracture mechanisms of injection molded Cr₃C₂/Al₂O₃ composite

The wear resistance and fracture mechanisms of Cr₃C₂/Al₂O₃ composites were investigated with a pin-on-disk test configuration against a silicon carbide sphere at room temperature in unlubricated sliding. The results suggest that the microcracking induced from residual stresses could play an important role in predicting the wear behavior. Although the addition of Cr₃C₂ to Al₂O₃ matrix improved its crack growth resistance, it enhanced the wear resistance. The mechanisms of material removal was related to the failure of the particle-matrix interface, resulting in particle pullout, wear debris and chipping of the matrix. A microabrasive mechanism and microplastic deformation were also observed. The worn-induced surface residual stress (-142 MPa) was similar to that induced by no. 270 diamond wheel grinding (-158 MPa).