Effects of Reinforcing Material Content on Physical Properties of C-Al-Si-Ti Coatings Prepared by Flame Spray Technique

Abstract

In this work, flame spray technique was used to deposit coatings of C-Al-Si-Ti reinforced with different contents of Fe-Cr alloy on stainless steel surfaces to protect these surfaces from corrosion due to their continuous exposure to mechanical stresses and high temperatures. Spray parameters, mainly spray angle of 90°, spray distance of 15-20cm between the gun nozzle and the sample to be coated, a particle speed of up to 100 m/s, and a melting point exceeding 1200°C, were controlled to develop much more homogeneous and dense microstructures. The hardness of the coated surfaces was determined and found to enhance, whereas both porosity and water adsorption were found to decrease, indicating an improvement in coating adhesion and a reduction in structural defects. The results also showed a decrease in thermal conductivity as a result of increased dispersion of heat carriers (Fe-Cr) within the structure. Therefore, an optimal ratio of the reinforcing material was determined to achieve a balance between mechanical strength and thermal efficiency, making these coatings good candidates for engineering applications operating in harsh environments that require high resistance to corrosion and thermal stresses.