The mechanical response in compression ofA2014 and A14wt Cu alloys with equiaxedmicrostructure in the semisolid state at high volumefraction of solid ( > 0.6) is studied. When the amountof liquid is low, deformation in compression is highlynon-uniform due to strain localization. In the rangeof conditions examined no phase segregation wasdetected. The stress-strain curve exhibits a peak atlow strain, around 510, and then decreases to aplateau value. Secondary phase particles in A2014 thatremain solid in the semisolid range of the alloy areresponsible for the lower peak and higher plateaustress compared to A14 wt Cu alloy. The effect of thegrain size for the alloys tested was small. Strainrate jump experiments show that the instantaneousstrain rate sensitivity in the semisolid state issimilar to that of the solid phase. As the volumefraction of solid decreases, the plateau stressbecomes rate insensitive to the strain rate jump. Theresults allow the relative importance to be assessedof various mechanisms responsible for resistance toflow of semisolid alloys with equiaxed microstructure in compression.
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