单晶镍基合金[001]取向拉伸蠕变期间的有限元分析  

Microstructure Evolution and FEM Analysis of [001] Orientation Single Crystal Nickel-based Superalloy During Tensile Creep

作　　者：张姝[1] 孟磊[2] 田素贵[3] 张静[1] 苏勇[1] 

机构地区：[1]沈阳化工大学机械工程学院,辽宁沈阳110142 [2]沈阳师范大学软件学院,辽宁沈阳110034 [3]沈阳工业大学材料科学与工程学院,辽宁沈阳110870

出　　处：《沈阳化工大学学报》2010年第4期349-355,共7页Journal of Shenyang University of Chemical Technology

基　　金：国家自然科学基金资助项目(50571070);辽宁省教育厅基金资助项目(2004C004)

摘　　要：通过[001]取向的镍基单晶合金拉伸蠕变期间的组织形貌观察,确定合金的组织演化特征;采用三维应力应变有限元方法计算立方γ/γ′两相共格界面的von Mises应力分布,研究施加应力对合金中γ/γ′两相应力分布及γ′相定向粗化规律的影响.结果表明:施加拉应力可改变立方γ/γ′两相的应力分布,使不同晶面发生晶格收缩与扩张应变,其中,(100)和(010)晶面沿平行于应力轴方向产生晶格扩张应变,可诱捕较大半径的Al、Ti原子,是使其γ′相沿扩张晶格的法线定向生长成为类似筛网层状结构的组织演化规律.并进一步提出拉应力蠕变期间,发生元素扩散和γ′相定向生长的驱动力.By means of the tensile creep property measurement of [001] orientationed single crystal nickel-based superalloy and microstructure observation,the characteristics of microstructure evolution are determined.Using the stress-strain finite element method（FEM） for calculating the von Mises stress in the coherent interface of the cubic γ/γ′ phases,the influence of the applied stress on the stress distribution of the cubic γ/γ′ phases is investigated for validating the regularity of γ phase directional coarsening.Results show that the distribution of the von Mises stress in the cubic γ/γ′ interfaces may be changed by the applied stress,and different crystal lattice contraction and expansion strain of surface occur,in which,the lattice expanding strain on（100） and（010） planes under the action of the applied stress may trap the Al,Ta atoms with bigger radius to promote the directional growth of γ′ phase along the normal direction of the expanding lattice,after the alloy crept is identified as the γ′ phase transformed into the layer-structure along the direction perpendicular to the stress axis.This is thought to be the regularity of γ′ phase directional coarsening during creep of the alloy,furthermore,proposing the driving force of the elements diffusion and directional coarsening of γ′ phase.

关 键 词：单晶镍基合金 组织演化 蠕变 有限元分析 

分 类 号：TG132.2[一般工业技术—材料科学与工程]