【摘要】 研究了微量硅元素在GH907低膨胀高温合金中的存在形式、分布特征及对第二相析出的影响。结果表明,硅促进合金中Laves、G相沿晶界析出,细化晶内ε相并增加其数量,使晶界ε相的形貌由连续分布的薄片状改变为离散分布的小块;第二相中的硅含量远高于合金平均硅含量;晶界上硅含量比晶内高数倍并随时效时间延长进一步富集。更多还原

【Abstract】 The distribution of Si in the phases and its influence on the quantity and morphologyof the precipitates in GH907 superalloy has been investigated using metallograph, TEM, X-raydiffraetometer, Auger electron spectroscopy,chemical phase analysis. It is demonstrated that the small addition of Si accelerates the precipitation of Laves, G phases along grain boundaries,makes phase finer within grains and ameliorates the shape of ε phase at grain boundary from continuous thin film to small block. The content of Si in secondary phases and on grain boundaries is much higher than the average content of the alloys.更多还原