Effects of silver

cobalt and germanium on microstructure and mechanical properties of the investment casting Be-Al alloy were investigated by tensile testing at room temperature

SEM（scanning electron microscope）observation and EDS（energy dispersive spectrometer）analysis.The results indicate that alloying element

such as Ag

Co and Ge

cannot change the microstructure of the alloy

and they strengthen the alloy as a result of strengthening aluminum alloy matrix.Compared with those of Be-Al matrix alloy

tensile strength and yield strength

elongation of the alloy with Ag

Co and Ge are greatly increased.Mechanism of alloying element strengthening alloy was analyzed theoretically.As a result

the alloying elements are beneficial not only for improving the brittleness but also for bonding the interface of Be-Al alloy.