Effect of Substrate Preheating on Cracking and Wear Resistance of Laser-Cladded Tribaloy T-800 Coatings on DD5 Single-Crystal Alloy

This study aims to investigate the impact of substrate preheating on the cracking and wear resistance of laser-clad T-800 alloy coatings on DD5 single-crystal alloy substrates. Two different conditions, namely non-preheated (22 °C) and preheated (300 °C), were employed to deposit T-800 alloy coatings on the surface of DD5 single-crystal alloy using laser cladding technology. The experimental results reveal that substrate preheating at 300 °C reduces the degree of variation in microstructure morphology within each region of the coating. This reduction effectively mitigates the internal stresses caused by the difference in solidification rates of the various parts of the coating, thereby preventing coating cracking. Additionally, the presence of Ni in the DD5 substrate enhances the dilution effect on the coating. Compared to the non-preheated condition, the preheated condition increases the Ni content in the primary Laves phase, secondary spherical Laves phase, and Co-based solid solution of the coating by 6.6