A new hybrid suspension and solution precursor thermal spray for wear-resistant silicon carbide composite coatings

Silicon Carbide (SiC) coatings offer exceptional wear resistance and excellent tribological characteristics; however, it is a challenging material to be thermally sprayed due to a lack of melting point. In this study, a hybrid, single-step suspension and solution precursor feedstock design is proposed, consisting of a SiC sus-pension modified with Yttrium Aluminium Garnet (YAG) precursors, for thermal spraying of SiC/YAG coat-ings. The decomposition of SiC was restricted in all spray campaigns. The solid loading of SiC (from 10 wt% to 20 wt%) and YAG phase (from 20 wt% and up to 50 wt%) were varied in an attempt to improve wear perfor-mance, enhance coating cohesion, and minimise porosity of the studied coatings. Among all studied coat-ings, 60 wt% SiC/40 wt% YAG and 50 wt% SiC/50 wt% YAG coatings at a 10 wt% solid loading were the best-performing coatings, demonstrating a promising wear resistance up to a sliding distance up of 1000 m, a dense coating structure with porosity at 0.4 +/- 0.2%. The feedstock design opens up a new method to process materials which are difficult, if not impossible, to process using a conventional thermal route.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

Automated summary

In this study, a hybrid feedstock design of SiC/YAG coatings for thermal spraying is proposed, and the solid loading and phase content are varied to improve the performance of the coatings. The results show that the best-performing coatings have a promising wear resistance and a dense coating structure with minimal porosity.