Wetting of grain boundaries in Al by the solid Al3Mg2 phase

Abstract

The microstructure of binary Al100−x –Mg x (x = 10, 15, 18 and 25 wt%) alloys after long anneals (600–4000 h) was studied between 210 and 440 °C. The transition from incomplete to complete wetting of Al/Al grain boundaries (GBs) by the second solid phase Al3Mg2 has been observed. The portion of completely wetted GBs increases with increasing temperature beginning from T wsmin = 220 °C. Above T wsmax = 410 °C all Al/Al GBs are completely wetted by the Al3Mg2 phase.