【摘要】 本文研究了含微量Ｌｉ的Ｎｉ３Ａｌ合金力学性能，结果发现Ｌｉ能提高Ｎｉ３Ａｌ的屈服强度，适量Ｌｉ能改善Ｎｉ３Ａｌ室温塑性，其断口形貌由Ｎｉ３Ａｌ合金的沿晶断裂变为混晶断裂；但Ｌｉ不能改善Ｎｉ３Ａｌ合金的中温脆性，对Ｎｉ３Ａｌ＋Ｂ合金室温塑性影响也不大。ＸＰＳ研究表明，Ｌｉ偏聚于Ｎｉ３Ａｌ合金晶界。本文给出了Ｌｉ提高多晶Ｎｉ３Ａｌ塑性的初步解释。更多还原

【Abstract】 The mechanical properties of Ni3Al alloys containing trace Li have been studied. It is found that trace Li may improve their yield strength and a proper amount may improve the ductility of polycrystalline Ni3Al alloys and change the fracture model from the inter-granular to the mixture of inter-and trans-granular. But neither improvement over brittleness at medium temperature nor effect on the ductility of polycrystalline Ni3Al+B alloys is satisfactory. XPS seems to indicate that Li atoms segregate to grain boundaries of Ni3Al alloys. According to this, preliminary explications of Li ductiling Ni3Al alloys might been made.更多还原