Exceptional mechanical properties of ultra-fine grain Mg-4Y-3RE alloy processed by ECAP

Precipitation hardenable WE43 magnesium alloy containing yttrium and rare earth elements was processed by ECAP. Microstructure, phase composition, mechanical properties and texture of the processed material was investigated by several complementary techniques. Substantial precipitation during ECAP led to exceptional grain refinement with the resulting average grain size of ~ 340 nm. The processed material exhibited previously unreported weak texture without a typical component usually observed in magnesium alloys processed similarly. The observed texture resulted from a massive particle-induced recrystallization during the processing through ECAP. The ultra-fine grain microstructure, the high density of Mg5RE particles and the specific texture resulted in the significant strengthening of the ECAPed material. The yield compression strength of ~ 427 MPa was by 340% higher than that of the initial as-cast condition and by 210% higher than that of the peak age-hardened one.