半固态A356合金浆料的新型制备技术  

A New Technique for Preparation of Semi-solid A356 Aluminum Alloy Slurry

作　　者：裴胜[1] 毛卫民[1] 杨小容[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《铸造技术》2007年第8期1039-1042,共4页Foundry Technology

基　　金：国家自然科学基金项目资助;项目编号50374012;国家重点基础研究规划项目;项目编号2006CB605203;国家"863"计划项目;项目编号:2006AA03Z115

摘　　要：采用直管浇注法制备了半固态A356铝合金浆料,获得了金属半固态加工要求的细小、球状的"非枝晶"组织,并分析了浇注高度和浇注温度对组织形成过程的影响。实验结果表明:直管在该工艺中起到了增加形核的作用;合适的浇注高度和低温浇注有利于形核;随着浇注高度的提高,初生-αAl晶粒逐渐从蔷薇状向球状和颗粒状转变,晶粒形貌也逐渐变好;随着浇注温度的降低,初生-αAl晶粒向球状或颗粒状转变,分布均匀,圆整度好。在本实验条件下,最佳的浇注高度为430 mm;合适的浇注温度为630～615℃。所得浆料从中心到边缘经历了一个从球状向破碎蔷薇状、再向枝晶状组织转变的过程。Fine spherical nondendritic grains of primary microstructure required by semi-solid forming was successfully obtained using the pouring method of vertical tube to prepare the A356 alloy slurry. The influences of the pouring height and the pouring temperature were analyzed. The results show that the tube plays a role in nucleation; Appropriate pouring height and low pouring temperature favor nucleation. With increasing the pouring height, primary α-Al gradually changed from rosettelike to spherical and granular shape and the morphology become better. With decreasing the pouring temperature, primary a-AI become globular and granular, and they are distributed more uniformly and more rounded. On the condition of the experiment, the optimum pouring height is 430 mm, the appropriate poring height is 630℃～615℃. The microstructure obtained changes from globular, broken rosette-like to dendritic morphology from the core to the edge of slurry.

关 键 词：直管浇注法 A356铝合金 半固态 浆料 

分 类 号：TG244.2[金属学及工艺—铸造]