Influence of nano-WC-12Co powder addition in WC-10Co-4Cr AC-HVAF sprayed coatings on wear and erosion behaviour

WC-10Co-4Cr coatings deposited by activated combustion-high velocity air fuel (AC-HVAF) spray process are the most commonly used system for different components prone to wear/erosion The aim of this work is to investigate the influence of nano-WC-12Co powder addition in WC-10Co-4Cr AC-HVAF sprayed coatings on wear and erosion behaviour. Therefore, in this work, nano-WC-12Co powder was added to the sub-micron WC-10Co-4Cr powder in order to improve the hardness of WC based AC-HVAF coatings. The result shows that 15% addition of nano-WC-12Co will improve the hardness of AC-HVAF coating from 1677 to 1873 HV0.3 due to the embedding of nano-WC-12Co powder. Sliding wear test and slurry erosion test were chosen to evaluate the effect of adding nano-WC-12Co powder. The wear and erosion resistance of AC-HVAF coated samples go up with the addition of nano-WC-12Co powder, in addition, the coating hardness has also Increased. The coatings have been characterised by scanning electron microscope (SEM), microhardness tester and X-ray diffractometer (XRD) The results indicated that the sample with 15% addition of nano-WC-12Co to WC-10Co-4Cr based AC-HVAF coating has the best wear and erosion resistance In addition, this also demonstrated that it is possible to fabricate the nanostructured WC-10Co-4Cr coating with low porosity and high hardness by AC-HVAF spray deposition with reasonable thermal spraying parameters Crown Copyright (C) 2010 Published by Elsevier B.V All rights reserved.