非枝晶A356合金半固态重熔加热时的组织演变  

Microstructural Evolution of A356 Non-dendritic Alloy During Semi-solid Remelting

作　　者：胥锴[1] 刘徽平[1] 刘政[2] 刘萍[1] 

机构地区：[1]江西理工大学材料与化学工程学院,江西赣州341000 [2]江西理工大学教务处,江西赣州341000

出　　处：《热加工工艺》2006年第1期19-22,共4页Hot Working Technology

摘　　要：采用光学显微镜和图相分析仪,研究了用电阻炉对液相线浇铸法制备的半固态A356合金进行二次加热过程中的组织变化。结果表明:在固液两相区内共晶体首先重熔,共晶相中的Si相通过向α相中扩散溶解,其团块状α相逐渐演变成球状;随着加热温度的升高,α相的生长和球化的速度变快;保温温度过高或保温时间过长,试样易发生变形。二次加热最佳工艺为585℃下保温30min,此时,晶粒平均直径为42.6μm,晶粒平均圆度为2.13。The changes in structure of liquidus casting A356 aluminum alloy during remelting in resistance furnace were studied by means of optical microscope and image analysis apparatus. The results show that the eutectic is remelted first and the Si-phase in eutectic dissolve in a way of diffusion toward α phase which gradually evolve into spheroidal shape in solid-liquid phase zone. The globe rate of α phase increase with the remelting temperature increasing. When the holding temperature is much higher or the holding time is much longer, the samples are susceptible to deformation. The best technical parameters of remelting is 585℃ for remelting temperature and 30 min for heat preservation time. Under these conditions, its average equal-area-circle grain diameter is 42.6μm and the average is 2,13.

关 键 词：A356合金 二次加热 组织演变 非枝晶组织 

分 类 号：TG146[一般工业技术—材料科学与工程]