Tribological and adhesion behaviour of hard alloy powder NiCrBCSi(Fe) coatings thermally sprayed on 60CrMn4 steel

摘要

This paper aims to show the relationship between, on one hand, the microstructure of deposition and post-deposition conditions, and on the other hand, the adherence and wear resistance of alloyed poly-powders nickel bases coatings thermally sprayed on a 60CrMn4 steel substrate. The adherence to steel substrate was determined using a shear test for adhesion, and the tribological behaviour of coating has been studied using a simple block-on ring tribometer. The spraying powder and coating micro structure were investigated by combination of X-ray diffraction, electron microprobe and scanning electron coupled to an analyser (EDX). Certain coating present a good adhesion and better wear resistance in the presence of bond coating and cyclic post-annealing at 650℃. That is explained by the microstructure duplexes of top coating composed the hard phase type Ni_3(BC) and the matrix bases reinforced by fine Cr precipitates, improved by cyclic post-annealing.