PROCESSING, STRUCTURE AND TRIBOLOGICAL BEHAVIOR OF TIC-REINFORCED PLASMA-SPRAYED COATINGS

The plasma spraying of TiC-reinforced wear resistant coatings, and a s tudy of their structure and tribological behaviour are the subject of this paper. HVOF WC-Co coatings, which are well established hard facin g coatings, were investigated for comparison with the coatings tested in the present study. Based on scientific criteria, modifications of t he carbide and the binder phase of the NiCr-TiC system were realised. Strengthening of the NiCr matrix, achieved by alloying the matrix with Fe, Al and Ti, proved to be beneficial for the coating tribological b ehaviour, as evaluated by pin-on-disk tests. The NiCr-based coatings r einforced with a solid solution (Ti,Ta)C showed better tribological be haviour than the coatings reinforced with just TiC particles. In unlub ricated sliding under ambient conditions, the WC-Co coatings showed be tter tribological behaviour than the TiC-based coatings. The coating s tructure, wear track, counterbody and debris investigation contributes in better understanding the coating wear performance. (C) 1998 Elsevi er Science S.A. All rights reserved.