OXIDATION BEHAVIOR OF LASER CLADDED NI-SI-TI-C COATINGS AT 1100 deg C

摘要

Waspaloy is a typical Ni-based superalloy that widely used for flue gas turbine blades, and its strengthening phase is Ni_(3)(Al,Ti). Laser cladding is one of the most effective methods for repairing damaged gas turbine blades. TiC particulate reinforced Ni_(3)(Si,Ti) intermetallic matrix composites (IMC) were laser cladded on Waspaloy using Ni-Si-Ti-C powder. The oxidation tests were performed at 1100 deg C for 48 h and 95 h in air. The specimens before and after oxidation tests were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron probe microanalysis (EPMA). Based on SEM and XRD results, the mechanisms of oxidation for the coatings were discussed.