▎ 摘　　要

Mechanical and tribological properties of nanocomposites with silicon nitride matrix with addition of 1 and 3 wt.% of multilayered graphene (MLG) platelets were studied and compared to monolithic Si3N4. The wear behavior was observed by means of the ball-on-disk technique with a silicon nitride ball used as the tribological counterpart at temperatures 25 degrees C, 300 degrees C, 500 degrees C, and 700 degrees C in dry sliding. Addition of such amounts of MLG did not lower the coefficient of friction. Graphene platelets were integrated into the matrix very strongly and they did not participate in lubricating processes. The best performance at room temperature offers material with 3 wt.% graphene, which has the highest wear resistance. At medium temperatures (300 degrees C and 500 degrees C) coefficient of friction of monolithic Si3N4 and composite with 1%MLG reduced due to oxidation. Wear resistance at high temperatures significantly decreased, at 700 degrees C differences between the experimental materials disappeared and severe wear regime dominated in all cases. (C) 2014 Elsevier Ltd. All rights reserved.