Impact of NiCrAlY-APS coating laser remelting on high-temperature oxidation resistance

This research focused on enhancing the high-temperature oxidation resistance of NiCrAlY-APS coatings by modifying their surface through remelting with a continuous fiber laser. The process parameters included laser power and scan rate. The high-temperature oxidation test was conducted for 200 h at a temperature of 1,100 °C. An examination of the coating was done by applying optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Following 200 h oxidation at a temperature of 1100 °C, the original coating displayed combination of aluminum oxide and spinel. The laser remelting process for the purpose of modifying the surface ensured uniform growth aluminum oxide layer (α-Al₂O₃) the oxidation examination. Following 200 h of oxidation at a temperature of 1100 °C, the original coating displayed combination of aluminum oxide and spinel. The surface remelting process for the purpose of modifying the surface ensured uniform growth aluminum oxide layer (α-Al₂O₃) the oxidation examination. The reduction in grain size which is caused by laser remelting could prevent Al₂O₃ oxide wrinkling. Laser remelting creates Y-Al particles on the coating's surface, which, in turn, create sites for oxidation without diffusion. This leads to α-Al₂O₃ phase formation in the oxidation's initial stages. Ultimately, this process ensures long-term thermodynamic stability. Such a process could serve as a new and alternative approach for modifying MCrAlY coatings.