EMBRITTLEMENT BEHAVIOR OF 7075 ALUMINUM ALLOY IN LIQUID METAL Ga
7075铝合金在液体金属Ga中的脆断行为

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.