AlSi7Mg合金低过热度半连续铸造组织的重熔演变  

Microstructural Evolution of AlSi7Mg Alloy Prepared by Semi-continuous Casting at Low Superheat during Reheating

作　　者：赵大志[1] 于福晓[1] 何克准[2] 刘芳[2] 左良[2] 

机构地区：[1]东北大学材料成型与控制工程研究所 [2]东北大学材料各向异性与织构工程教育部重点实验室

出　　处：《特种铸造及有色合金》2011年第10期917-920,共4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(2007AA03Z516;2008AA030701;2009BAE80B01);国家自然科学基金资助项目(50734006;50771030)

摘　　要：采用光学显微镜及图像分析仪,研究了AlSi7Mg合金低过热度半连续铸造坯料在不同加热温度及保温时间下重熔的微观形貌及尺寸特征,结合差热分析的方法研究了加热过程中组织演变及晶粒长大过程。结果表明,重熔加热温度及保温时间共同影响着合金重熔组织的演变进程,随着加热温度升高及保温时间延长,晶粒逐渐球化并长大。加热温度越高,组织演变速度越快;保温时间越长,晶粒球化并长大越明显。有效控制AlSi7Mg合金重熔加热温度及保温时间,能够获得均匀、圆整且相对细小的半固态浆料组织。Microstructure and grain size of AlSi7Mg alloy billet prepared by semi-continuous casting at low superheat,which was reheated at different heating temperatures and holding time,were observed by optical microscope and image analyzing software to understand microstructure evolution and grain growth during reheating process combining with differential scanning calorimetry（DSC） . The results reveal that microstructure evolution is closely related with reheating temperature and holding time. With increasing in heating temperature and holding time,grain is grown spherically,and microstructure evolution is faster and faster with increasing in heating temperature. Grain is grown more and more spherically with extending in holding time. The AlSi7Mg alloy billets with homogeneous and spherical as well as fine structure can be prepared by effectively controlling reheating temperature and holding time.

关 键 词：半连续铸造 ALSI7MG合金 重熔 组织演变 

分 类 号：TG249.7[金属学及工艺—铸造]