Abstract
The oxidation and recrystallization behaviors of Ni-base single crystal superalloy, CMSX-2 were investigated to determine the condition of the preparation for TLP-bonding operations. The Paying surfaces of CMSX-2 were worked by the shot peening, fine cutting and mechanical polishing treatments and the degree of working of treated surfaces was evaluated by the hardness test and X-ray diffraction method. CMSX-2 was heat-treated at 1173-1589 K for 3.6 ks in vacuum of 4 mPa. The mechanically polished surface was slightly oxidized after heat treatment even in the vacuum atmosphere of 4 mPa. The thickness of an oxide film increased with increasing the heating temperature and the surface roughness of the faying surface. Recrystallization occurred at the surface after heat treatment at above 1423 K when the hardness was increased more than Hv600 by the shot peening treatment, while the mechanically polished or fine cut surfaces didn't recrystallized. Based on these results, it was clearfied that the mechanically polishing with fine abrasive grit could be used for the preparation of faying surface of CMSX-2 before bonding operation.
