Deformation Assisted Nucleation of Continuous Nanoprecipitates in Mg-Al Alloys
26 Pages Posted: 12 Nov 2019 Publication Status: Accepted
Conventional aging of magnesium alloys results in a low number density of laths providing poor precipitate strengthening. We demonstrate that dynamic strain aging (DSA) of Mg-Al (6 and 9 wt.%) alloys produces a high density of nanoprecipitates with small aspect ratios within grain interiors. Nanoindentation of these samples yields much higher hardness values compared to conventionally peak-aged samples. The precipitate number density correlates with the dislocation density observed in experiments and calculated using a strain hardening model. We argue that dislocation multiplication increases the number of heterogeneous precipitate nucleation sites and thereby enhances precipitation.
Keywords: magnesium alloys, dynamic strain aging, strain hardening, dislocation, precipitation nucleation and growth, phase transformation
Suggested Citation: Suggested Citation