Tribological behaviour of thermally sprayed Ti–Cr–Si coatings

Quasicrystal coatings are potential candidates for many industrial applications, e.g., high hardness, low friction coefficient, low surface energy and high thermo-electric power. An attempt to produce a quasicrystal by plasma and flame spraying Ti60Cr32Si8 (at.%) alloy powder has been reported in a previous paper. This paper focuses on the tribological properties of atmospheric plasma sprayed Ti60Cr32Si8 (at.%) alloy coatings produced using two sets of spraying parameters. First coating contains a large amount of oxide (APSO) and the other coating has the metallic phases retained (APSM). For this purpose a reciprocating ball on block tribometer has been used. The test has been conducted using various speeds and loads, while the sliding distance has been kept constant. The worn surfaces have been studied using scanning electron microscope. A correlation of microstructural features, process parameters, tribotest parameters and wear mechanism has been conducted. The wear behaviour of each coating has been found to depend strongly on both its phase content and tribotest parameters. In general, the coating with higher oxide content has been found to be more wear resistant. Such coatings are potential candidates for paper and printing industry.