一种单晶镍基合金蠕变期间γ'相的定向粗化机制  

A DIRECTIONAL COARSENING MECHANISM OF THE γ＇-PHASE DURING CREEP OF A SINGLE CRYSTAL NICKEL-BASE SUPERALLOY

作　　者：田素贵[1] 周惠华[1] 张静华[1] 杨洪才[2] 徐永波[1] 胡壮麒[1] 

机构地区：[1]中国科学院金属研究所材料疲劳与断裂国家重点实验室 [2]东北大学材料科学与工程系,沈阳110006

出　　处：《金属学报》1998年第6期591-596,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金!59571039

摘　　要：对[001]取向单晶镍基合金恒载拉伸蠕变不同阶段的组织形貌进行了SEM，TEM观察和EDAX成分分析，研究了γ＇相定向粗化过程及机理结果表明：蠕变初期，两相邻γ＇相呈侧平面对接方式，沿垂直于应力轴方向定向生长为类似筛网的核状组织，外加应力使γ＇／γ界面共格应变减少，应变能降低，释放的能量是促使合金元素定向扩散形成筏状γ＇结构的驱动力．The microstructures of a [001] single crystal nickel--base superalloy at differentstages of the constant loading tensile creep were observed by means of TEM and SEM, and thechemical compositions of γ and γ＇ phases were analyzed by EDAX in order to investigate theprocess and mechanism of the directional coarsening of γ＇ phase. The results showed that themesh--like rafts were formed along the direction normal to the stress axis in a mode of side--planelink in primary creep. The applied stress resulted in the decrease of the coherent strain and theenergy of the γ＇/γ interfaces. Thus, the energy released was supposed to be the driving force forthe directional diffusion of elements, leading to the formation of the γ＇ rafts.

关 键 词：单晶镍基合金 蠕变 定向粗化 扩散驱动力 

分 类 号：TG111.2[金属学及工艺—物理冶金] TG132.32[金属学及工艺—金属学]