Sliding wear behaviour of plasma sprayed WC-NiCrBSi coatings at different temperatures

Plasma sprayed coatings are used for reducing the wear losses of many industrial components. It appears that few studies have considered the influence of the bulk temperature on the wear resistance of coatings. To study these effects in a Ni-based alloy reinforced with small quantities of WC, wear tests were carried out in an oscillating friction machine with alumina cylinders as counterbodies. The specimens were tested at 20, 250 and 500°C nominal temperature; the sliding speed was kept constant at 0.15 m/s, and the normal load ranged from 50 to 200 N. The experimental programme reveals the coating behaviour and the wear rates of the material in terms of normal load and temperature. Considerable differences were found between the wear rates of the counterbodies. The analysis of the worn specimens by scanning electron microscopy (SEM) and energy dispersive X-rays spectroscopy (EDAX) provides information about the main mechanism associated with each condition.