Abstract
Atomized aluminum powder mixed to magnesium alloy (AZ31) turning chips with Mg-12 and 40 mol% Al compositions, were mechanically alloyed (MA) for 54 ks. For the surface improvements of the magnesium alloy, the obtained MA powders of Mg-12 mol% Al (12AlMA) and Mg-40 mol% Al (40AlMA) were stacked on magnesium alloy (AZ31 and AM60) sheets, then hot-rolled at various temperatures. After the roll-bonding, Mg17Al12 phase precipitates from super-saturated α-Mg in 12AlMA powder and it also forms from amorphous phases in 40AlMA powder. The hardness in the bonded MA powder layer becomes higher than as-MA powder particles. When roll-bonding were performed for 12AlMA powder over 400 K and for 40AlMA powder over 480 K, Mg and Al mixed each other by diffusion phenomenon in interface of MA layer and Mg alloy sheet. Fracture strength in 3-point bending of magnesium alloy sheet increases by bonding of MA powder.
