作　　者： ; ; ; ; ;

机构地区： 福州大学材料科学与工程学院

出　　处： 《材料热处理学报》 2009年第4期189-193,共5页

摘　　要： 运用相图计算技术,预测了名义成分为Ti-22Al-27Nb的Ti2AlNb基合金在热处理过程中的相结构与相转变,得到了该合金的相转变温度、相比例和各相的成分等重要信息,将材料热力学中的亚晶格模型和第一性原理总能计算相结合,对Ti2AlNb基合金中的主要组成相—O相(有序正交相)中的合金元素在各个亚晶格上的占位分数和有序化行为进行了深入研究,表明O相的有序-无序转变属于具有连续变化特征的二级相变,预测结果与现有实验结果相当吻合。 The phase structure and phase transition were predicted by using the so-called CALPHAD approach.And the mole fractions of the constituted phases in Ti2AlNb-based alloy and the mole fractions of the constituted elements in each phase were obtained.The order-disorder transitions of the dominating phase in Ti2AlNb-based alloy,denoted as O phase,were investigated by combining sublattice model with first-principle total-energy calculations.The site occupancy fractions of the alloying elements on the sublattices were calculated. The order-disorder transformation of the 0 phase belongs to the second-order transition with a continuous character. The predicted results agree well with the available experimental data.

关 键 词： 基合金 相平衡 有序 无序转变 相图计算 第一性原理计算

领　　域： [金属学及工艺] [金属学及工艺]