Multi-axial compression of the mushy zone occurs in various pressurized casting processes. Here, we present a drained triaxial compression apparatus for semi-solid alloys that allow liquid to be drawn into or expelled from the sample in response to isotropic or triaxial compression. The rig is used to measure the pressure-dependent flow stress and volumetric response during isothermal triaxial compression of globular semi-solid Al-15 wt pct Cu at 70 to 85 vol pct solid. Analysis of the stress paths and the stress–volume data show that the combination of the solid fraction and mean effective pressure determines whether the material undergoes shear-induced dilation or contraction. The results are compared with the critical state soil mechanics (CSSM) framework and the similarities and differences in behavior between equiaxed semi-solid alloys and soils are discussed.

糊状区的多轴压缩在各种加压铸造过程中发生。在这里，我们介绍了一种用于半固态合金的排水三轴压缩设备，该设备允许液体响应各向同性或三轴压缩而被吸入样品或从样品中排出。该装置用于测量球状半固态Al-15 wt pct Cu在70至85 vol pct固含量的等温三轴压缩过程中与压力有关的流动应力和体积响应。对应力路径和应力-体积数据的分析表明，固体分数和平均有效压力的组合决定了材料是否经历剪切诱导的膨胀或收缩。