(东北大学 材料与冶金学院， 沈阳 110006)
摘 要: 提出了液相线半连续铸造制备铝合金半固态浆的新工艺，研究了液相线半连续铸造7075合金的微观组织及其在二次加热过程中的变化。在液相线温度下(908 K)半连续铸造的7075合金组织为均匀、细小的蔷薇状组织，晶粒平均等积圆直径为29.7μm，晶粒平均圆度为1.87。 经二次加热后，铸造组织逐渐转变为等轴晶。 在849 K下加热60]min后，晶粒平均等积圆直径为57.6 μm，平均圆度为1.49。在869 K下加热30 min后，晶粒平均等积圆直径为47.2μm，平均圆度为1.54。结果表明，液相线半连续铸造可以获得理想的7075合金半固态浆料。
关键字: 液相线铸造； 半连续铸造； 半固态； Al合金； 非枝晶
（School of Materials and Metallurgy， Northeastern University，
Shenyang 110006， P.R.China）
Abstract: A new process， liquidus semi-continuous casting(LSC) to produce semi-solid slurries of aluminum alloy, was presented. The casting and remelted microstructures of 7075 alloy cast by LSC were studied. The microstructures cast at liquidus temperature(908 K) by LSC is uniform， fine and rose flowered. The average equal-area-circle grain diameter is 29.7 μm and the average roundness is 1.87. The casting microstructures are gradually turned into equiaxed grains by being remelted. After the casting billet are soaked at 849 K for 60 min， the average equal-area-circle grain diameter is 57.6 μm and the average roundness is 1.49. After the casting billet is soaked at 869 K for 30 min， the average equal-area-circle grain diameter is 47.2 μm and the average roundness is 1.54. The results show that fine semi-solid slurries of 7075 alloy can be obtained by LSC.
Key words: liquidus casting; semi-continuous casting; semisolid; Al alloy; non-dendrite
