Microstructure evolution and deformation features of single crystal nickel-based superalloy containing 4.2% Re during creep  

一种含4.2%Re单晶镍基合金在蠕变期间的组织演化与变形特征(英文)

作　　者：田素贵[1] 梁福顺[1] 黎阿男[1] 李晶晶[1] 钱本江[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870

出　　处：《Transactions of Nonferrous Metals Society of China》2011年第7期1532-1537,共6页中国有色金属学报（英文版）

基　　金：Project(50571070) supported by the National Natural Science Foundation of China

摘　　要：By means of microstructure observation and measurement of creep properties,the high temperature creep behaviors of a single crystal nickel-based superalloy containing Re were investigated.Results show that the single crystal nickel-based superalloy containing 4.2% Re possesses a better creep resistance at high temperature.After being crept up to fracture,the various morphologies are displayed in the different areas of the sample,and the γ＇ phase is transformed into the rafted structure along the direction vertical to the applied stress axis in the regions far from the fracture.But the coarsening and twisting extents of the rafted γ＇ phase increase in the regions near the fracture,which is attributed to the occurrence of the larger plastic deformation.In the later stage of creep,the deformation mechanism of the alloy is that the dislocations with [01^-1]and [011] trace features shear into the rafted γ＇ phase.The main/secondary slipping dislocations are alternately activated to twist the rafted γ＇ phase up to the occurrence of creep fracture,which is thought to be the fracture mechanism of the alloy during creep.通过组织形貌观察及蠕变曲线测定,研究了一种含Re镍基单晶合金的高温蠕变行为。结果表明:含4.2%Re单晶合金在1060-1100℃温度区间具有较好的承温能力,但表现出较强的施加应力敏感性。经高温蠕变断裂后,在试样不同区域γ′相具有不同的组织形貌,在远离断口区域γ′相形成的筏状组织与施加应力轴方向垂直,而在近断口区域,筏状γ′相的粗化及扭曲程度的增大为该区域发生较大塑性变形所致。在蠕变后期,合金的变形机制是迹线方向为[011]和[011]的滑移位错切入筏状γ′相,主、次滑移系交替开动,使筏状γ′相发生扭折形成不规则的扭曲形态,直至发生断裂是合金的蠕变断裂机制。

关 键 词：single crystal nickel-based superalloy RE CREEP microstructure evolution deformation mechanism 

分 类 号：TG146.15[一般工业技术—材料科学与工程]