Effect of in-situ oxidation on the nanomechanical evolution of Fe-base coating with ceramic particles produced by internal rotating plasma spraying

Abstract

In this work, we investigated FeCrMo coatings with 35 wt% ceramic, which were produced on a cylinder surface by an internal rotating plasma spraying and oxidized in air. The ceramic particles consisted of 80 wt% alumina and 20 wt% zirconia, which can improve the mechanical properties of the coating. For microstructural characterization, scanning electron microscopy was combined with energy dispersive X-ray analysis and electron probe micro analysis, and the nanomechanical properties were measured by a nanoindentation tester. The structure of Fe-base coating matrix consists of Al 2 O 3 , ZrO 2 and a small amount of mixed Fe–Cr oxides, and the ceramic particles exhibit a uniform distribution. During oxidation, a mixed oxide layer containing Fe 2 O 3 and Fe 3 O 4 forms on the surface of the Fe-base coating, and the thickness of the oxide layer increases with increasing oxidation temperature. Due to the in-situ oxidation, the nanohardness and Young's modulus of the Fe-base coating decreased with increasing oxidation temperature. The nanohardness evolution of Fe-base coatings oxidized at different temperatures is discussed.