摘要
采用一种富含SiC晶种的Al-30Si-5C晶种合金对Al-18Si合金进行细化试验。结果表明,该晶种合金对初生Si有良好的细化效果,添加量为1%、搅拌后保温15min,初生Si平均晶粒尺寸由108μm细化至35μm。由EDS及DSC分析可知,SiC晶种为初生Si的异质形核衬底。细化机理为:(1)基本满足要求的错配度;(2)Si在SiC表面吸附及偏聚使富Si层优先满足形核过冷度需求;(3)SiC台阶凹面形貌有利于晶胚形核。
The refining behavior and heterogeneous nucleating behavior of Al-30Si-5C master alloy on primary Si in Al-18Si alloys were described.The results show that the mechanical stirring can accelerate the refining effect of Al-30Si-5C master alloy on primary Si and a shorter holding time is also a promotion factor.The average size of primary Si grains can be decreased from 108μm to 35μm with 1%Al-Si- C master alloy addition by applying mechanical stirring and holding temperature for 15min.The EDS and DSC analysis indicates that SiC particles can act as the heterogeneous nucleation substrate of primary Si.Besides,the refining mechanism was discussed from the following aspects.①the basically appropriate crystallographic orientation relationship between Si phase and SiC phase,②adsorption and segregation of Si element on SiC particles enabled the rich Si layer to satisfy the nucleation supercooling degree, ③surface morphology of SiC particles favorable for nucleation of embryos.
作者
韩梦霞
陈海霞
孙谦谦
刘桂亮
刘相法
Han Mengxia;Chen Haixia;Sun Qianqian;Liu Guiliang;Liu Xiangfa(Key Laboratory of Liquid-solid Structural Evolution and Processing of Materials,Ministry of Education,Shandong University;Binzhou Bohai Piston Co.,Ltd.)
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2018年第12期1365-1369,共5页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(51571133)
作者简介
第一作者:韩梦霞,女,1991年出生,硕士研究生,山东大学材料液固结构演变与加工教育部重点实验室,济南(250061),电话:0531-88392006,E-mail:hanmengxia1126@163.com
