STUDY OF ACOUSTIC EMISSION DURING DEFORMATION OF MAGNESIUM ALLOY

Abstract

Acoustic emission (AE) of magnesium alloy WE 43 in process to compress was studied. Typical grain size of alloy was between 3-25 microns. AE parameters (activity, total number of impulses, average amplitude) were analyzed in correlation with deformation curves. It was shown that yield stress at compressing WE43 alloy with different grain size is in good agreement with Hall-Petch relationship. Acoustic emissions started at stress significantly lower than macroscopic yield stress. Maximum of curve activity AE coincide to the value of macroscopic yield stress. The increase of grain size leads to the both rise of AE activity so and average amplitude impulse. The increase of number of high-amplitude signals in spectrum AE was detected also. It was suggested that the rising share of high-amplitude impulses in spectrum AE with grain growth was associated with increase in the numbers of starts moving pile-ups of dislocations and twinning in individual grains.