| Summary: | 碩士 === 國立高雄應用科技大學 === 機械工程系 === 106 === In this study, we designed optimal coating parameters for Co-Mo-Cr-Si powder plasma thermal sprayed on Inconel 718 alloy based on Taguchi experimental method. Four spraying factors with three levels were used, the factors including primary gas flow (Argon), secondary gas flow (Hydrogen), powder feed rate and spray current. Performing and discussing of coating related experimental analysis to metallographic microstructure, bonding strength, Rockwell surface hardness (HR 15N) and abrasion performance.
As the result, the study found that the un-melted particles, voids and porosity, and oxides in coating structure affect the quality of coating directly. It demonstrated the correlation between various spray parameters and coating quality. We shall select the most appropriate spray parameter under different environmental conditions to achieve best coating quality. According to the tensile test with different coating thicknesses, thicker coating will produce greater internal stress after coating cooled then caused a poorer mechanical bonding ability between coating and material surface. According to the wear resistance, we found that the coating for Co-Mo-Cr-Si spray has 14 times more wear resistance than Inconel 718 material, successfully achieved the efficacy of wear resistance to coating.
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