[011]取向镍基单晶合金在拉伸蠕变期间的组织演化与有限元分析

来源期刊：金属学报2011年第1期

论文作者：张姝 田素贵 于慧臣 苏勇 于兴福 于莉丽

文章页码：61 - 68

关键词：[011]取向单晶； 镍基合金； 组织演化； 蠕变； 有限元分析

Key words：[011]取向单晶； 镍基合金； 组织演化； 蠕变； 有限元分析

摘    要：采用弹性应力-应变有限元方法计算了[011]取向单晶镍基合金中γ/γ′两相共格界面的von Mises应力及应变能密度的分布特征,研究了施加拉应力对γ/γ′两相界面von Mises应力分布及γ′相定向粗化规律的影响.结果表明:[011]取向单晶镍基合金经热处理后,组织结构是立方γ′相以共格方式嵌镶在γ基体相中,并沿〈100〉方向规则排列.当沿[011]方向施加拉应力时,与近(010)γ′晶面的基体通道相比,近(001)γ′晶面的基体通道有较大的von Mises应力,在主应力分量的作用下,与(010)γ′晶面相比较,(001)γ′晶面沿[010]γ′方向发生较大的晶格扩张应变,可诱捕较大半径的Al原子和Ti原子,是促使γ′相沿[001]方向定向生长成为纤维状筏形组织的主要原因.

Abstract: By means of the elastic stress-strain finite element method (FEM), the distribution features of the von Mises stress, strain energy density and the influences of the applied stress on the von Mises stress at γ/γ’ phases interface and γ’ phase directionally coarsening regularity in a [011] oriented single crystal nickel-based superalloy were investigated. Results show that after heat treatment, the microstructure of the superalloy consists of the cubic γ’ phases embedded coherently in theγmatrix, and γ’ phases arranged regularly along the <100> direction. Compared to the matrix channel near (010)_γ’ plane, the bigger von Mises stress are produced within the matrix channel near (001)_γ’ plane when the tensile stress is applied along the [011] direction. Compared to (010)_γ’ plane, the larger expanding lattice strain occurs on the (001)_γ’ plane along the [010]_γ’ direction under the action of the principal stress component, resulting in the Al, Ti atoms with bigger radius to be trapped by the larger strain zone, which is the main reason of promoting the γ’ phase grown directionally into the strip-like rafted structure.