The Comparison of the AST 908, AST 915 and AST 928 of Micro-Hardness of Tungsten Based Alloy Films on AISI 1050 Steel by HVOF Coating Method

Abstract

In this study, the commercial powder tungsten based alloys was sprayed by using high velocity oxygen fuel (HVOF) method on AISI 1050 steel substrate. These films of powder tungsten based alloys of AST 908, AST 915 and AST 928 were included. The powder was mainly composed of tungsten (W), Chromium (Cr), Nickel (Ni) and Cobalt (Co) with an average particle size in the range of 10-45 μm. The microstructure and compositional analysis was used by the scanning electrode microscopy (SEM) and energy dispersive spectroscopy (EDS) respectively. The micro-hardness of coating films was investigated by Vickers micro- hardness tester. The SEM results exhibited good deposition between the coating films with the specimens (AISI 1050 steel). Accordingly, the coating films showed a very homogeneous microstructure. In addition, the micro-hardness of substrate was 81.30% lower than the AST 908 particles. Finally, the AST 908, AST 915 and AST 928 coating improved the micro- hardness of 1559.3 HV, 1468.4 HV and 1306.2 HV respectively