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A high-Mg2Si content Al alloy was extruded by equal channel angular pressing(ECAP) for 8 passes at 250 ℃ and an ultrafine-grained structure with an average grain size of about 1.5 μm was achieved.The coarse skeleton-shaped Mg2Si phase presenting in the as-cast alloy are significantly fragmented into fine rod-shaped as well as equiaxed particles mostly less than about 230 nm and become relatively dispersed.The tensile strength 192.8 MPa and the elongation up to 31.3% at ambient temperature are attained in the 8-pass ECAPed alloy versus 163.3 MPa and 9.1% in the as-cast alloy.High-temperature creep test at 250 ℃ reveals that the ECAPed sample exhibits a high elongation close to 100% at a relatively high creep rate 7.64×10-5 s-1,compared to the elongation 56% at a low strain rate 1.74×10-7 s-1 in the as-cast alloy.
A high-Mg2Si content Al alloy was extruded by equal channel angular pressing (ECAP) for 8 passes at 250 ° C and an ultrafine-grained structure with an average grain size of about 1.5 μm was achieved. The coarse skeleton-shaped Mg2Si phase presenting in the as-cast alloys are significantly fragmented into fine rod-shaped as well as equiaxed particles mostly less than about 230 nm and become relatively dispersed. tensile strength 192.8 MPa and the elongation up to 31.3% at ambient temperatures are attained in the 8- pass ECAPed alloy versus 163.3 MPa and 9.1% in the as-cast alloy. High-temperature creep test at 250 ° C reveals that the ECAPed sample exhibits a high elongation close to 100% at a relatively high creep rate of 7.64 × 10-5 s- 1, compared to the elongation 56% at a low strain rate 1.74 × 10-7 s-1 in the as-cast alloy.