过共晶Al-Si合金初晶Si相的细化机理  

Refinement Mechanism of Primary Si in Hypereutectic Al-Si Alloy

作　　者：周志敏[1] 王娜[1,2] 李勇[3] 管曙荣[2] 

机构地区：[1]东北大学理学院 [2]上海宝钢集团公司 [3]焦作万方铝业股份有限公司

出　　处：《特种铸造及有色合金》2012年第2期99-102,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51034002)

摘　　要：利用熔体快速凝固和液态结构遗传原理,针对A390合金近液相线铸造半固态坯料的制备,探讨过共晶Al-Si合金初晶Si演变及细化的机理。试验研究了铸造速度为120mm/min和冷却水流量为0.05m3/min条件下,高于液相线10～100℃范围内不同的浇注温度对初晶Si尺寸形貌的影响。结果表明,近液相线半连续铸造过程可以对初晶Si的形核和长大提供合理的速度匹配,有利于均匀形核和抑制初晶Si的异常生长,仅控制工艺参数即可实现在不添加变质剂和细化剂条件下对初晶Si尺寸、形貌和分布的改善,得到具有细小且均匀分布的初晶Si相,这对于简化工艺、节约资源和降低成本具有实际意义。Mechanism of the evolution and refinement of the primary Si in A390 alloy was analyzed based on rapid solidification and the heredity theory of liquid structures in A390 alloy billets in the case of the near liquidus semi-continuous casting . Influence of the pouring temperature from 10 ℃ to 100 ℃ above the liquidus on the morphology of the primary Si in A390 alloy was investigated under the conditions of casting velocity 120 mm/min and cooling water flux 0.05 m3/min. The results show that the near liquidus semi-continuous casting process is in favor of uniform nucleation and abnormal growth restraint of the primary Si due to an appropriate match in rate of the nucleation and growth. The morphology and distribution of the primary Si in the alloy can be improved by controlling the casting parameters without adding the refiner and modifier to the melt, showing great significance to the processing simplifying, resource saving and cost reducing.

关 键 词：半固态成形 近液相线半连续铸造 过共晶AL-SI合金 初晶SI 

分 类 号：TG146[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]