Thermal stability of a laser-clad NiCrBSi coating hardened by frictional finishing

Abstract

Eddy-current testing of fatigue degradation upon contact fatigue loading of gas powder laser clad NiCrBSi-Cr 3 C 2 composite coating Abstract. Frictional treatment decreases surface roughness of a NiCrBSi laser coating and increases its microhardness and abrasive wear resistance. Even after softening annealing at 900 С, the coating subjected to frictional treatment preserves its advantage in hardness and wear resistance over the original clad coating. Annealing at 1000 С after frictional treatment ensures less effective growth of the hardness and wear resistance of the coating as compared to annealing of the undeformed coating due to the limited precipitation of large Cr 23 C 6 carbides on the deformed surface, which form a wear-resistant framework.

Increasing the resistance of a NiCrBSi coating to heat wear by means of combined laser heat treatment

“…2492980) [5], involving laser cladding with additional high-temperature annealing. The proposed new approach to the formation of heat-resistant coatings by combined laser-thermal method (with high-temperature annealing of the clad coating) was applied to enhancing the wear resistance of nickel-based alloy specimens produced by an additive laser technique, namely, by direct laser material deposition [6] and to producing a coating strain-hardened by friction treatment with a sliding indenter [7].…”

“…However, in [4,5,7], the conclusion about the heat resistance of the coatings was based only on hardness and wear resistance measurements at room temperature after cooling from the annealing (tempering) temperature. The aim of this paper is to study the possibility of increasing the wear resistance of a NiCrBSi coating, under considerable friction heating induced by sliding friction at high (above 5 m/s) speeds, by combined laser heat treatment.…”