半固态ZL201A铝合金浆料的制备  

Preparation of Semi-solid ZL201A Aluminum Alloy Slurry

作　　者：毛卫民[1] 朱达平[1] 张佳宾[1] 姚景文[1] 

机构地区：[1]北京科技大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2010年第5期393-395,共3页Special Casting & Nonferrous Alloys

基　　金：国家高技术研究发展计划(863计划)资助项目(2006AA03Z115);国家重点基础研究发展计划(973计划)资助项目(2006CB605203)

摘　　要：利用低过热度浇注和弱电磁搅拌方法制备了半固态ZL201A铝合金浆料,浇注温度分别为678、663、648℃,利用光学显微镜观察了不同条件下的浆料组织。试验结果表明,随着浇注温度的降低,半固态ZL201A铝合金浆料内部组织中的初生α-Al由蔷薇状向球状转变,晶粒尺寸逐渐变小,分布更均匀。同时,浆料边缘和底部组织中的初生α-Al的形貌由粗大的枝晶向蔷薇状转变。对于半固态ZL201A铝合金浆料的制备,较佳的浇注温度为663℃。电磁搅拌均匀了ZL201A铝合金液的温度场,加大了同时凝固的区域,细化了初生α-Al晶粒;同时结晶潜热的集中释放有助于蔷薇状初生α-Al的根部熔断,加速了球状初生α-Al的形成。The semi-solid ZL201A alloy slurry was prepared by the low superheating pouring at 678,663,648℃ and weak electromagnetic stirring method,and microstructure of the samples was observed by optical microscope.The results reveal that with decreasing in pouring temperature,primary α-Al grains in the semi-solid ZL201A aluminum alloy slurry are changed from rosette to spherical shape with refinement of grain size and more homogeneous distribution,meanwhile,that in the edge and bottom of the slurry are converted from coarse dendrite into rosettes.The appropriate temperature for preparation of semi-solid ZL201A aluminum alloy slurry is 663℃ under the given conditions.The refinement of primary α-Al grains is attributed to the weak electromagnetic stirring homogenizing the temperature field of liquid ZL201A alloy and widening the region of simultaneous solidification,meanwhile,the latent heat of the ZL201A aluminum alloy is released during a shorter period,which promotes the secondary arm roots of the rosette α-Al grains to be melted,accelerating the formation of spherical α-Al grains.

关 键 词：半固态 浇注温度 电磁搅拌 ZL201A铝合金 显微组织 

分 类 号：TG249.9[金属学及工艺—铸造]