EFFECT OF RECRYSTALLIZATION ON ENVIRONMENTAL EMBRITTLEMENT OF A NI3AL-BASED ALLOY

The effects of recrystallization on room temperature tensile propertie s and susceptibility to test environments (air versus vacuum) of a Ni3 Al-based alloy have been investigated. The results indicate that recry stallization treatment not only increases ductility but also reduces s usceptibility to test environment of the alloy. The fracture mode has also been observed in the scanning electron microscope (SEM). It was f ound that air promoted transgranular cleavage fracture and reduced the amount of ductile fracture for unrecrystallized and partially recryst allized microstructures. In completely recrystallized specimens, the d uctile fracture mode remained unchanged when test environment changed from vacuum to air.