【摘要】 采用电镀Pt气相渗铝的方法,在不同厚度(0.8,1.0和1.3 mm)的镍基单晶高温合金基体表面制备了单相的β-(Ni, Pt)Al涂层.利用SEM/EDS及EPMA等表征方法,研究试样在1100℃热暴露200 h过程中涂层/基体界面的微观结构演变和各组元的元素分布.结果表明:不同基体厚度的PtAl涂层/镍基单晶高温合金试样在1100℃热暴露200 h后截面微观形貌无明显差异,热暴露36 h后在互扩散区下方均形成了分布有TCP相的二次反应区,热暴露200 h后基体厚度为0.8,1.0和1.3 mm的试样中SRZ厚度分别为37,35和34μm;不同基体厚度的PtAl涂层/镍基单晶高温合金试样,在1100℃热暴露200 h后成分分布无明显差异,涂层与基体间主要发生Ni, Co, Cr和Ru的外扩散及Pt和Al的内扩散.更多还原

【Abstract】 Single phase β-(Ni, Pt)Al coating was prepared on the nickel-based single crystal superalloy with different substrate thickness via electroplating Pt and gaseous aluminizing. The microstructure evolution and element interdiffusion behavior between coating and substrate during thermal exposure at 1100℃ for up to 200 h were characterized by scanning electron microscopy(SEM) equipped with energy dispersive spectroscopy(EDS) and electron probe micro-analyze(EPMA). The results show that there is no significant difference in the cross-sectional morphologies of the PtAl coating/superalloy samples with different substrate thickness(0.8 mm, 1.0 mm and 1.3 mm) after thermal exposure at 1100℃ up for 200 h. Secondary reaction zone(SRZ) containing topological close packed phases(TCP) is formed behind the interdiffusion zone(IDZ). The thickness of the SRZ for the samples with substrate thickness of 0.8 mm, 1.0 mm and 1.3 mm were 37 μm, 35 μm, 34 μm, respectively. There was no significant difference in the composition profiles of the samples with different substrate thickness during thermal exposure for 200 h. During the thermal exposure process, the inward diffusion of Pt and Al from the coating to the substrate are accompanied with the outward diffusion of Ni, Co, Cr and Ru.更多还原