溅射NiCrAlY渗Al涂层的高温氧化行为

HIGH TEMPERATURE OXIDATION BEHAVIOR OF A SPUTTERED NiCrAlY COATING WITH ALUMINIZING

用SEM、XRD和EPMA等手段,研究了溅射NiCrAlY涂层渗Al前后在1000℃和1100℃的高温氧化行为.结果表明,溅射涂层在1000℃形成了单相的α-Al2O3,具有优异的抗氧化性能;但在1100℃由于Al的过度消耗而失去保护作用.渗Al涂层在1000℃快速增长θ-Al2O3相,使其抗氧化性能稍逊于溅射涂层;在1100℃表面形成了以α-Al2O3为主的保护膜,抗氧化性能优于溅射涂层.

A nanocrystalline Ni - 30Cr - 8Al - 0.5Y coating was deposited on a Ni - base superalloy by magnetron sputtering. Post - aluminizing was performed on the sputtered coating to improve the high - temperature oxidation resistance. The isothermal oxidation behaviors of the sputtered coating with and without aluminizing at 100012 -110012 have been investigated using TGA, SEM/EDS, XRD and EPMA, respectively. The results indicated that the sputtered NiCrAlY coating possessed excellent oxidation resistance at 100012. Because of the excessive consumption of Al in the coating, it lost protective ability at 110012. The mass gain of the aluminized NiCrAlY coating was a little higher than that of the sputtered coating due to the formation of the rapid growth 0 - Al2O3 phase at 100012. At 110012 the oxidation resistance of the latter was better than that of the former as a result of the formation of a continuous and protective Al2O3 scale.