Tribological study of WC produced by plasma pressure compaction

The purpose of this preliminary study was to determine the sliding wear performance of a number of binderless WC specimens produced by using the Plasma Pressure Compaction-(PC)-C-2 (R) process. Six different processing conditions were employed to obtain the WC samples by varying the powder size particles between 0.2 mu m and 1.2 mu m at two compaction temperatures 1600 degrees C and 1700 degrees C, respectively. Sliding friction tests against an alumina ball were performed in a tribometer, at constant room temperature and relative humidity between 60% and 65%. The worn samples were analyzed by means of SEM and optical profilometry. Very low wear constant values, k, of approximately 10(-8) mm(3)/N m were obtained in all cases, indicating an excellent tribological performance. It has been shown that the wear behavior is not considerably influenced by the processing temperature, nor by the initial particle size of the WC powder. A Vickers hardness value of approximately 20 GPa has been found for those samples which had the highest initial particle diameter of 1.2 pm. The fracture toughness, K-IC, was determined by means Vickers indentation with a maximum load of 30 kg load. Values between 6.6 +/- 0.7 MPa/root m to 8.7 +/- 0.8 MPa/root m were calculated for the samples under study. (c) 2005 Elsevier Ltd. All rights reserved.