定向凝固Ni_3Al合金高温变形后的显微组织特征  

MICROSTRUCTURE FEATURES IN DIRECTIONALLY SOLIDIFIED Ni_3Al ALLOY AFTER HIGH TEMPERATURE DEFORMATION

作　　者：谷月峰[1] 林栋梁[1] 单爱党[1] 陈家光 胡凡 曹涵清 

机构地区：[1]上海交通大学国家教委高温材料及高温测试开放实验室,上海200030 [2]上海宝山钢铁研究所,上海201900

出　　处：《金属学报》1998年第4期351-355,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金!59331011

摘　　要：利用金相、扫描电镜和透射电子显微镜研究了定向凝固Ni3Al合金高温变形后的显微组织特征研究结果表明，当变形速率较快时，原始柱状晶晶界无明显变化，晶内无明显亚结构存在；当变形速率较慢，合金呈现超塑变形时，变形初期柱状晶晶界呈现“锯齿状”，后期原始柱状晶界消失，代之以晶粒尺度约为15mm的晶粒带，晶粒带中既有小角度晶界，也有大角度晶界合金在超望变形时发生了连续回复与再结晶的过程.Optical microscopy, transmission electron microscopy and scanning electron microscopy were used to examine microstructure features of the directionally solidified Ni3Al alloy deformed under tension at high temperature. The results show that initial columnar grain boundaries have not obviously changed during the deformation under higher strain rate and there are no substructure within the columnar grains. When strain rate is lower, the initial columnar grain boundaries firstly change into sawtooth shape and then evolve into small grain belts with increasing strain during superplastic deformation. The average grain size in belt is about 15 mm containing both low angle grain boundaries and high angle grain boundaries. It is suggested thata continuous recovery and recrystallization process took place during superplastic deformation in DS Ni3Al alloy.

关 键 词：定向凝固 NI3AL 高温变形 显微组织 

分 类 号：TG113.12[金属学及工艺—物理冶金] TG146.15[金属学及工艺—金属学]