The deformation and acoustic emission of aluminum-magnesium alloy under non-isothermal thermo-mechanical loading

The following study investigates the deformation behavior and acoustic emission in aluminum-magnesium alloy under conditions of non-isothermal thermo-mechanical loading. The accumulation of deformation in the alloy, in conditions of change from room temperature to 500°C, occurs in two temperature intervals (I, II), characterized by different rates of deformation. The rate of deformation accumulation is correlated with acoustic emission. With load increasing in cycles from 40 to 200 MPa, the value of the boundary temperature (Tb) between intervals I and II changes non-monotonically. In cycles with load up to 90 MPa, the Tb value increases, while an increase up to 200 MPa makes Tb shift toward lower temperatures. This suggests that the shift of boundaries in the region of low temperatures and the appearance of high-amplitude pulses of acoustic emission characterize the decrease of the magnitude of thermal fluctuations with increasing mechanical load, leading to the rupture of interatomic bonds in an elementary deformation act.