EBSD技术对大晶粒Ni-42Al合金超塑变形过程组织演变的研究  

EBSD study of the microstructural evolution of large grained Ni-42Al alloy during superplastic deformation

作　　者：胡静[1] 林栋樑[2] 

机构地区：[1]江苏工业学院材料科学与工程系,常州213016 [2]上海交通大学材料科学与工程学院,教育部高温材料及高温测试开放实验室,上海200030

出　　处：《中国体视学与图像分析》2007年第4期278-281,共4页Chinese Journal of Stereology and Image Analysis

基　　金：国家自然科学基金资助项目(No.59895150)

摘　　要：采用EBSD分析技术研究1075℃、初始应变速率为1×10^-3S^-1试验条件下大晶粒Ni-42A1合金超塑变形过程中的组织演变。研究发现，变形前大晶粒Ni-42A1合金中小角度晶界比例极低，均以大角度晶界为主，且某几个特定角度的大角度晶界占有明显优势。在超塑变形过程中，持续有取向差5°以下的小角度晶界产生。随变形量的增大，新形成的小角度晶界取向差增加，转变为取向差较大的5～15°小角度晶界，进而转变为15°以上的大角度晶界。小角度晶界的产生速率与小角度晶界转变为较大角度晶界的速率趋向一动态平衡。小角度晶界向较大角度晶界不断转变的结果使大角度晶界数量不断增加，最终导致晶粒显著细化。The microstructural evolution of large-grained Ni-42A1 alloy during superplastic deformation at 1075℃ with initial strain rate of 1 × 10^-3s^-1 was studied using EBSD technique. The results show that before deformation, the most grain boundaries belong to high angle boundaries, with several special angles as domain. During deformation, very low angle grain boundaries with misorientation less than 5°formed continuously. With the increase of the deformation, the new-formed very low angle grain boundaries in- creased their misorientation and turned to grain boundaries with larger misorientation between 5 - 15°, and finally turned to high angle grain boundaries with misorientation larger than 15°. There exists a sort of balance between the formation of new low angle grain boundaries and their turn to higher angle grain boundaries. The low angle grain boundaries＇s forming and turning to higher angle grain boundaries made the number of high angle grain boundary increased continuously, thus resulted in grains being refined remarkly.

关 键 词：EBSD NiA1 金属间化合物 大晶粒 

分 类 号：TG115[金属学及工艺—物理冶金]