Microstructure and interfacial adhesion of high velocity oxy‐fuel‐sprayed MoB–CoCr alloy coating on 316L stainless steel

Abstract

In this article, a newly developed MoB-CoCr alloy coating was deposited on 316L stainless steel substrate by high velocity oxy-fuel thermal spraying process. The microstructures and interfacial adhesion of the alloy coating were determined by scanning electron microscopy, X-ray diffraction and three-point bending. The results show that the coating consisted of ternary transition metal boride matrix phases (CoMo 2 B 2 , CoMoB) and a little amount of binary borides (MoB and CrB), the former composed of partially amorphous phase. The formation of the amorphous phase was attributed to the high cooling rates of molten droplets and the proper powder compositions. In the interfacial adhesion measurement, the delamination of the coating is induced during the three-point bending test, and the interfacial fracture toughness is analyzed using a finite element analysis model. The critical load is determined by comparing the load versus deflection curves obtained by finite element analysis under assumed no crack conditions with the experimental data, and other inputs are determined by test.

Fabrication, morphology and mechanical properties of Al2O3–Al graded coatings on China low activation martensitic steel substrates

“…In Figs (b), (c) and (d), some cracks were also observed at the interfaces. If the adhesive force at the interface is too weak, cracking and exfoliation can readily occur as an exogenic process . The same experimental preparation methods were used for all the samples and therefore the potential exogenic effect on the samples was also constant.…”

Corrosion Behavior of FeB-30 wt.% Al0.25FeNiCoCr Cermet Coating in Liquid Zinc

“…However, it was not particularly designed for galvanizing; thus, its corrosion and wear resistance need to be strengthened. To prolong its lifetime, MoB/CoCr [6,7] and WC/Co [8][9][10] cermets coatings are deposited on the steel using high-velocity oxygen fuel (HVOF) method [11][12][13][14]. There are still some issues to be resolved such as depositing even MoB/CoCr or WC/Co coating on 316L stainless steel.…”