7075铝合金在液体金属Ga中的脆断行为  

EMBRITTLEMENT BEHAVIOR OF 7075 ALUMINUM ALLOY IN LIQUID METAL Ga

作　　者：刘晓敏[1] 乔利杰[1] 诸武扬 

机构地区：[1]北京科技大学材料物理系,北京100083

出　　处：《金属学报》1998年第6期615-620,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金!59671042;19891180

摘　　要：用WOL恒位移试样研究了7075铝合金在液体金属Ga中的脆断行为金相跟踪观察表明，Ga吸附后首先促进局部塑性变形，在缺口前方形成四下的塑性区，然后脆性激裂纹形核．液体金属脆断的临界应力强度因子．反向加载（位移V＜0）时，液体金属脆性激裂纹在远离缺口顶端的拉应力区中形核，微裂纹向拉应力区扩展而中止于压应力区反向加载时，试作断裂的名义应力强度因子为．所有断裂试样均为沿晶断口．The liquid metal--induced embrittlement(LME) of 7075 aluminum alloy byGa was investigated by using modified WOL notched specimen. The results showed that the adsorption of Ga atoms could facilitate localized plastic deformation of the base metal and there was an observable concave plastic zone around the notch tip. Then a microcrack would initiate when the adsorption -- facilit at ed plastic deformation reached to a crit ical condit ion. The threshold stress intensity factor of LME under the applied tensile stress was 1.7 MPa'ml/2. When the specimen was loaded in the opposite direction(the displacement V <0),a microcrack would initiate in the tensile stress zone away from the notch tip. The microcrack would propagate towards tensile stress zone and arrest at compressive stress zone. The nominal threshold stress intensity factor for the inverse loading was 3.5 MPa'm1/2. The fracture surfaces of LME for all the specimens were intergranular.

关 键 词：铝合金 液体金属镓 表面能 应力强度因子 

分 类 号：TG111.91[金属学及工艺—物理冶金] TG146.21[金属学及工艺—金属学]