【摘要】 采用自行设计的SCR实验机制备A2017半固态合金,研究了SCR工艺参数对A2017半固态合金组织的影响。实验结果表明,合金液浇注温度和轧辊冷却水流量共同影响辊靴间隙中半固态合金的固相率,降低浇注温度或者增大冷却水流量,辊靴间隙高固相率合金区间增长,晶粒尺寸变小;减小辊靴间隙或者提高轧辊转速提高合金层流剪切强度,利于枝晶破碎;增大出口半固态浆料冷却速率能有效抑制晶粒继续生长,保留其完整的非枝晶半固态组织。合金液浇注温度为760～780℃,辊靴间隙为4～6mm,轧辊冷却水流量200～300ml/s条件下,SCR技术可获得浆料状A2017半固态合金,凝固后坯料为均匀、细小的非枝晶等轴晶组织,晶粒大小在40～50μm之间,SCR技术是一种制备半固态加工坯料的理想方法。更多还原

【Abstract】 The self-made SCR(Shearing/Cooling Roll process)machine was adopted to manufacture semisolid A2017 alloys. The effects of SCR process parameters on microstructure of the semisolid alloy were studied. The experimental results showed that both the pouring temperature of molten alloy and the flux of the cooling water of roll influenced the solid fraction of the semisolid alloy between the roll and shoe. Decreasing the pour temperature or increasing the flux of the cooling water could increase the solid fraction of semi-solid alloy and refined the grains. Decreasing the gap of between roll and shoe or increasing velocity of roll could increase shear strength and refine grains. Increasing cooling rate of slurry in die could hold fully semi-solid structures. Molten alloy was poured within 760～780℃. The gap of roll and shoe was 4～6mm. The flux of cooling water was within 200～300ml/s. The semisolid slurry could be obtained under above conditions. The fine and homogeneous non-dendrite microstructures whose grains size was between 40～50μm could be obtained in cooled billet. SCR technology is an ideal method to prepare semisolid billet.更多还原