点击次数：

论文类型：期刊论文

发表时间：2016-09-01

发表刊物：CHINA FOUNDRY

收录刊物：SCIE、ISTIC

卷号：13

期号：5

页面范围：316-321

ISSN号：1672-6421

关键字：ultrasonic treatment; Al-Si alloy; iron-containing intermetallics; modification

摘要：Iron is generally regarded as an unavoidable impurity in Al-Si casting alloys. The acicular Al3Fe and beta-Al5FeSi (or Al9Si2Fe2) are common iron-containing intermetallic compounds (IMCs) in conventional structure which have a detrimental impact on the mechanical properties. In this paper, ultrasonic field (USF) was applied to modify acicular iron phases in Al-12% Si-2% Fe and Al-2% Fe alloys. The results show that the USF applied to Al-Fe alloys caused the morphological transformation of both primary and eutectic Al3Fe from acicular to blocky and granular without changes in their composition. In the case of Al-Si-Fe alloys, ultrasonic treatment led to both morphological and compositional conversion of the ternary iron IMCs. When the USF was applied, the acicular beta-Al9Si2Fe2 was substituted by star-like beta-Al12Si2Fe3. The modification rate of both binary and ternary iron IMCs relates to the USF treatment duration. The undercooling induced by the ultrasonic vibration contributes to the nucleation of intermetallics and can explain the transformation effect.