大体积液态铝合金的净化和深过冷

DENUCLEATION AND HIGH UNDERCOOLING OF BULK ALUMINUM ALLOYS

采用无机盐类净化剂,在高频电磁悬浮熔炼装置上对大体积Al83Y10Ni7合金进行净化处理,获得了78.1℃的大过冷度;使用DSC技术和常规金相方法分析了深过冷熔体中的晶体形核和凝固组织。实验结果表明,在熔体的强制对流条件下,适当配比的无机盐净化剂有较强的微观净化效果,并使其微观组织明显细化。在自由凝固条件下,深过冷液态金属的细化效果仅受控于形核过冷度,与其体积的大小无关。

A183Y10Ni7 alloy is denucleated within a special inorganic salt on the electromagnetic levitation melting set-up. Large undercoolings up to 78.1℃ are achieved. The crystal nucleation and solidification microstructures of the undercooled melt are examined by the differential scanning calorimetry and common micrography. The experimental results show that the suitably composition of inorganic salt has a good denucleating effect on Al Y Ni alloys under the condition of forced melt convection and makes the microstructures of the alloy get fine apparently. And the refinement effect of the undercooled melt only depends on the undercoolings before the crystal nucleations take place without limitation of melt volume.