含Mg共晶Al-Si合金铸锭加热过程共晶Si形貌的演变  

Evolution of Si Morphology in Mg Containing Eutectic Al-Si Alloy Ingot During Heating Process

作　　者：赵刚[1] 石翔宇 田妮[1] 左良[1] 

机构地区：[1]东北大学材料各向异性与织构教育部重点实验室,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2014年第2期228-231,共4页Journal of Northeastern University(Natural Science)

基　　金：国家科技支撑计划项目(2009BAE80B01);教育部新世纪优秀人才支持计划项目(NCET-12-0110);中央高校基本科研业务费专项资金资助项目(N110410003);国家自然科学基金资助项目(51001022)

摘　　要：采用光学和激光共聚焦显微镜及扫描电镜等组织分析手段，研究了直径为110mm的Al—12．7Si-0．7Mg合金DC铸造铸锭在485℃盐浴加热保温过程中共晶Si形貌的演变．结果表明，在Mg的质量分数为0．7的共晶Al-Si合金半连续铸锭中，共晶si在金相组织中为点状和细条状的混合物，但其空间形貌为珊瑚状；该半连续铸锭在重新加热保温初期，共晶Si相空间形貌的演变主要是珊瑚状Si相的粗化，随后在共晶Si继续粗化、球化的同时，部分长杆状共晶Si相逐渐演变成糖葫芦状，然后分裂成颗粒并球化和粗化；该铸锭在485℃加热保温过程中，共晶Si颗粒直径的粗化与加热保温时间符合2．29～2．67次幂的关系．The evolution of the morphology of eutectic Si in the DC casting Al-12.7Si-0.7Mg ingot with 110 mm diameter during the salt bath heat treatment at 485 ℃ was studied by means of optical microscope （OM）, laser scan confocal microscope （LSCM） and scanning electron microscope（SEM）. The results showed that by OM the section morphology of the eutectic Si in the ingot of DC casting Al-12.7Si-0.7Mg alloy was the mixture of spot and strip, but its 3D morphology was coral like structure. The coral-like Si coarsened when the semi-continuous casting ingot was in the early stage of the reheating and holding treatment, furthermore, some of the long rod-like eutectic Si changed its morphology into the continued gourd-like shape which then broke up into granules getting coarsening and spheroidization afterwards, when the holding time of the heat treatment was prolonged. The diameter of the eutectic Si particle and the holding time were in accordance with a power of 2.29 - 2.67 relationship during heating and holding the ingot at 485 ℃.

关 键 词：AL-SI合金 半连续铸造 共晶硅 球化 珊瑚状 

分 类 号：TG146.2[一般工业技术—材料科学与工程]