Optimization of HVOF Spray Parameters for WC-Co-Cr Coatings on AMMC (Al-RHA) for Pump Impeller Protection

Present study investigates the enhancement of pump impeller materials using aluminium matrix composites (AMCs), specifically focusing on Al 7075 Alloy strengthened with rice husk ash (RHA) for enhanced durability and resistance to corrosion. It employs Thermal spraying using high-velocity oxygen-fuel (HVOF) to apply WC-Co-Cr powder, emphasizing low porosity, high adherence, and superior wear and corrosion resistance. By optimizing HVOF spray parameters using Taguchi L25 Orthogonal array, the research aims to minimize porosity and maximize hardness, addressing challenges in material dispersion, sustainability, and process control. The objective is to develop predictive models for the microhardness and porosity characteristics of WC–10Co–4Cr coating powder utilized through HVOF on AMMC substrates. AMMC substrates. Spray distance, carrier gas flow rate, powder feed rate, oxygen flow rate, and LPG flow rate are examined, with spray distance exerting the most significant influence on porosity, followed by powder feed rate and other parameters. This study contributes to improving coating characteristics crucial for industrial applications.