Determination of hardness of plasma-sprayed FeCrBSi coating on steel substrate by nanoindentation

In this paper, we develop a method for determining the hardness of FeCrBSi coating on a 1045 steel substrate. The nano-indents of the FeCrBSi coating exhibit obvious pile-up. The proposed method models the projected contact area as an equilateral triangle bounded by arcs to correct for the effect of pile-up on the contact area. The new method is described in detail and leads to improvement in obtaining coating hardness compared with the widely adopted Oliver–Pharr method.