Dry sliding wear mechanism of spark plasma sintered Si3N4/SiC composites on steel

In the present work, Si3N4-based composites were characterized by a relatively low friction coefficient in unlubricated sliding against a 100Cr6 steel ball. Si3N4-based composites containing different amounts of SiC were produced by spark plasma sintering at 1650 degrees C for 5 min with a uniaxial pressure of 40 MPa in a nitrogen atmosphere. In the wear test, the load, total distance and rotating speed were selected as 60 N, 120 m and 500 rpm, respectively. The wear tracks were examined by scanning electron microscopy (SEM) to estimate the wear mechanism. The results were evaluated using the friction coefficient-distance diagram. Si3N4-based composites showed significant decrement in wear by improving toughness with SiC powder reinforcement.