工艺条件对6061铝合金近液相线铸造微观组织的影响  

Microstructure of Near-liquidus Semi-continuously Casting 6061 Aluminum Alloy

作　　者：王娜[1,2] 周志敏[2] 路贵民[3] 赵大志[1] 

机构地区：[1]东北大学材料电磁过程研究教育部重点实验室 [2]东北大学理学院 [3]华东理工大学资源与环境工程学院

出　　处：《特种铸造及有色合金》2009年第6期508-511,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(50674032)

摘　　要：采用近液相线半连续铸造技术,制备了120mm×1600mm的6061铝合金半固态坯料,考察了铸造温度、铸造速度和冷却强度对铸锭组织的影响。结果表明,合金熔体在常规铸造温度(720℃)下获得的铸锭组织是粗大的枝晶,且组织极不均匀;在近液相线温度(657℃)下保温后铸造的铸锭组织均匀、细小、近球形。一次冷却强度的降低、二次冷却强度的增大均有利于均匀、细小的近球形组织的形成;铸造速度达到150mm/min时可以获得细小、均匀、近球形的6061半固态坯料组织。The semi-solid 6061 aluminum alloy billets with 120 mm in diameters and 1600 mm in length were prepared by near-liquidus semi-continuously casting.Effects of pouring temperature,pulling velocity and cooling rate on microstructure of the ingot were analyzed.The results indicate that the microstructure of ingot poured at 720 ℃ exhibits coarse dendrite with heterogeneous distribution,while that of poured at 657 ℃ exhibits homogeneous fine near-globular structure.The uniform and fine near-globular structure in the ingot can be easily formed with decreasing in firstly cooling rate and then increasing in cooling rate.In addition,the semi-solid 6061 aluminum alloy billets with uniformly fine near-globular structure can be observed with casting velocity of 150 mm/min.Near-liquidus semi-continuously casting is an effective method for preparing 6061 aluminum alloy semi-solid billets.

关 键 词：6061铝合金 近液相线半连续铸造 半固态坯料 微观组织 

分 类 号：TG292[金属学及工艺—铸造]