Abstract
A Ni-20 wt% Sn coating was deposited by the cold spraying method on steel substrate. The thickness of the deposited coating was approximately 50 μm and porosity was <1%. The coating microstructure consisted of a Ni solid solution with the presence of various intermetallics, which was confirmed by x-ray diffraction and electron microscopy. Stress-strain behaviour of this coating, both in planar and cross-sectional direction, was investigated under in-situ micro-pillar compression. It was found that strength and elastic modulus was slightly higher in the cross-sectional direction of the coating compared to that of the planar direction. The presence of intermetallics in the coating microstructure acts as a reinforcement medium to allow effective load bearing capacity of the coating. Loading direction during compression with respect to splat boundary orientation plays an important role in the mechanism of coating deformation. There was no substantial work hardening, due to the lubricating effect of SnO2 in the coating system.
•Successful deposition of Ni – 20 wt.% Sn coating of about 50 μm thickness•Coating microstructure consists of a dispersed intermetallic in solid solution.•Strength and elastic modulus is slightly higher in cross-sectional direction.•Fracture loading took place by slip/shear band formation along splats boundaries.•No substantial work hardening effect was noticed due to lubricating nature of SnO2.