Wear resistance performance of thermally sprayed Al3Ti alloy measured by three body micro-scale abrasive wear test

Abstract

Thermally sprayed aluminium alloys are often used as coatings to protect steel structures from corrosion. However, in many applications the alloys also need to be sufficiently wear resistant to prevent premature removal of the coatings. The addition of titanium to sprayed aluminium coatings is one approach to enhance the wear resistance. In this study the wear performance of a newly developed and commercially available aluminium coating with 3wt% Ti was studied in terms of its microstructure, hardness and wear resistance. Micro-scale abrasive wear tests were conducted on the pre-sprayed alloys, and the arc sprayed coatings produced from these alloys in order to determine the influence the spraying process has on the structure and wear properties of the coatings. The wear performance of the coatings with Ti was compared with a 99.5wt% Al coating, a thermally sprayed 13% Cr steel coating and with the mild steel substrate.Significant changes were observed in the microstructure of the sprayed coatings when compared with pre-sprayed alloys. The aluminium with 3wt% Ti coating exhibited a large increase in its hardness value compared with the pre-sprayed alloy and it was significantly harder than the 99.5wt% Al coating. It was observed that under micro-scale abrasive wear test conditions, the coefficient of wear of the coating with 3wt% Ti was 33% lower than that of the 99.5wt% Al coating and it was approximately the same as that of the 13wt% Cr steel coatings.