Microstructure and Wear Analysis of FeBCr Based Coating Deposited by HVOF Method

Abstract

Thermally sprayed coatings that are based on FeBCr-related alloy powders are widely used to improve properties such as the surface hardness and wear resistance of a variety of coated metal substrate materials. Gray cast iron is widely used in the automobile industry due to its low cost and performance. In this work Gray cast iron substrate is coated with FeBCr alloy powder to improve its performance. The microstructure and micro abrasive wear performance of both the uncoated substrates and the coated substrates were characterized by optical microscopy as well as by Scanning Electron Microscope (SEM). In addition, X-ray Diffraction (XRD) was undertaken in the partial characterization of the coating. The densely layered coating had porosity levels that were below 2.5 % and a high surface hardness, of the order of 980 HV0.1. The coating exhibited excellent wear resistance when subjected to the ball-cratering test method. The low coefficients of friction of hard coating on the substrate were recorded. The wear performance of the coating was nearly 82 % better than that of the substrate, with a 0.05 N load, even under severe three body abrasive conditions.

Keywords

• Fe based crystalline coating
• HVOF
• Microstructure
• XRD
• Microhardness