【摘要】 为了研究Inconel706合金宏观偏析“黑斑”区相变行为及析出相的形成特征,对黑斑区和正常区的相析出特征进行了系统的对比分析,并用热力学相计算手段对合金黑斑区的相变规律和元素的热力学平衡分配进行了计算分析。结果认为,Inconel706合金宏观偏析黑斑主要是由富Nb的Laves相和富Ti的η,δ相的严重偏聚粗化导致的。从黑斑的组织行为分析及热力学相计算可以认为,Nb在凝固过程中发生了极为明显的枝晶间液态偏聚,同时Ti和Al也有一定程度的偏聚,这些元素不同程度的液态偏聚行为是造成合金黑斑区相富集的主要原因。更多还原

【Abstract】 In order to illustrate the microstructural behavior with respect to heat treatment and freckle characterization, the freckle formation and their phase characterization in freckle areas were investigated by means of microstructure analysis approaches and a thermodynamic equilibrium phase calculation method in a Inconel 706 superalloy. These results show that, for freckle characterization, a large number of Laves, η and δ phases precipitate in freckle area due to the enrichment and segregation of Nb, Ti and Al during solidification. Equilibrium phase and liquid segregation calculation can give an reasonable interpretation of freckle feature for this alloy更多还原