受控扩散凝固技术(CDS)制备过共晶Al-18Si合金  

Hypereutectic Al-18Si Alloy Prepared by Controlled Diffusion Solidification(CDS) Technology

作　　者：周宏伟[1] 李元东[1,2] 马颖[1,2] 张心龙[1] 刘兴海[1] 

机构地区：[1]兰州理工大学材料科学与工程学院甘肃省有色金属新材料省部共建国家重点实验室 [2]兰州理工大学有色金属合金及加工教育部重点实验室

出　　处：《特种铸造及有色合金》2014年第1期37-41,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51064017)

摘　　要：采用受控扩散凝固(CDS)技术制备过共晶Al-18Si合金,研究了不同母合金成分在不同混合方式下混合对Al-18Si合金凝固组织中初生Si相尺寸、形貌及分布的影响。结果表明,在母合金过热温度相同的情况下,采用固态纯Al与液态Al-25Si混合,能够得到最佳的合金组织,其初生Si平均尺寸达到11.68μm,形状因子达到1.608,细化效果良好。分析表明,同种混合方式下,高Si母合金中Si含量越高,细化效果越好。当高Si母合金中Si含量较高时,液液混合能减少初生Si偏聚,得到良好的组织。当高Si母合金中Si含量较低时,固液混合得到的组织相对较好。The hypereutectic Al-18Si alloy was prepared by CDS technology,and the effects of precursor alloying component and mixing methods on the size,morphology and distribution of primary silicon phase in the alloy prepared were investigated by OM（optical microscope）.The results show that,at fixed overheating temperature of precursor Al-Si alloy,under solid pure Al mixing with liquid Al-25Si, the desirable microstructure in the alloy can be obtained,where the average size of primary Si is 11.68 μm with shape factor of 1.608.The analysis reveals that,at the same mixing method,the refining effect is increased with increasing in Si content.With a higher Si content in precursor Al-Si alloy,liquid Al mixing with liquid Al-Si alloy can weaken segregation of primary Si and refine grain size,while with a lower Si content in precursor Al-Si alloy,solid pure Al mixed with liquid precursor Al-Si alloy is a acceptable method.

关 键 词：过共晶Al-18Si合金 受控扩散凝固 母合金成分 混合方式 初生SI 

分 类 号：TG244.3[金属学及工艺—铸造]