倾斜式冷却剪切制备半固态Al-Mg合金

利用自制的实验装置对倾斜式冷却剪切技术制备半固态Al Mg合金进行了研究·液体合金在倾斜的冷却板表面非均匀形核并受到重力的剪切作用,合金逐渐从粗大等轴晶网络演化为细小的球形晶·控制浇注温度在660～690℃范围内可以获得良好组织的半固态坯料,很好地改善了常规铸造高Mg合金中出现的羽毛晶·冷却板表面性质对合金组织具有重要影响,表面干净并具有一定粗糙度的冷却板制备出的合金组织优良·

Preparation of Al-Mg-Based Semisolid Alloy by Inclined Cooling/Shearing

An experimental inclined cooling/shearing set-up was developed to prepare the Al-Mg-based semisolid alloy, the molten alloy nucleated heterogeneously on the inclined-cooling plate surface and was sheared under the action of gravity force, and its microstructure gradually evolved into fine spherical grain from coarse equiaxed grain network. By controlling casting temperature in the range of 660-690°C, the semisolid slabs with good microstructure were obtained, with the feather crystal which are usually found the high-Mg alloy slabs conventionally improved greatly. The surface conditions of cooling plate obviously affects the alloy microstructure, i.e., fine microstructure can be obtained if the cooling plate has a clean surface that is rough to a certain degree. The inclination angle of cooling plate is preferable in the range of 40°-50°.