【摘要】 采用磁控溅射方法在Ni基单晶高温合金上沉积NiCrAlY涂层,研究了真空热处理及高温氧化过程中,NiCrAlY涂层/Ni基单晶合金界面显微结构的变化及元素扩散行为。结果表明,原始涂层成分分布比较均匀,各元素分布在涂层/基体界面呈陡然变化。真空热处理时,涂层与基体间发生互扩散,NiCrAlY涂层的显微结构和相结构发生变化:涂层/基体界面区出现互扩散层(内、外扩散层);出现g-Ni3Al 和a-Cr两新相,导致涂层局部区域富Cr。1 000℃氧化200h后,涂层/基体界面区的互扩散层增厚,并且在其下的基体中出现扩散影响层。Ta在涂层中扩散时,置换了部分g-Ni3Al相中的Al,导致g相的晶格常数a0增大。更多还原

【Abstract】 A NiCrAlY coating was deposited on a Ni-base superalloy substrate by magnetron sputtering. The elemental diffusion and the microstructural change in the interface zone between the NiCrAlY coating and the substrate were investigated. It was shown that the elemental distribution in the as-sputtered NiCrAlY coating was homogeneous and had an abrupt change at the interface between the substrate and coating. During vacuum heat treatment, microstructure changed and a phase transformation took place in the coating because of interdiffusion between the substrate and coating. An interdiffusion layer (outer and inner diffusion layer) appeared and two new phases, g-Ni3Al and a-Cr, emerged from local Cr-rich regions in the coating. After 200h oxidation at 1 000℃, the interdiffusion layer thickened, beneath which diffusion influence layer emerged because of the further diffusion of elements. Ta replaced some of the Al in the g-Ni3Al phase, resulting in an increase of the lattice parameter a0 of g phase.更多还原