摘要
【目的】为细化Mg-Al-Si合金中的粗大Mg_(2)Si相,添加Al-5Ti-1B和稀土Y对Mg-5Al-5Si合金进行变质处理。【方法】熔炼制得不同成分的Mg-Al-Si合金,使用多种测试方法对变质前后合金成分、微观组织及力学性能进行分析,并讨论其变质机理。【结果】结果表明:在Mg-5Al-5Si合金中添加Al-5Ti-1B,初生相形貌由粗大块状转变为细枝晶状或多边形状,共晶相数量随着Al-5Ti-1B添加量的增加而减少,合金硬度显著提高,这是因为TiB_(2)为Mg_(2)Si提供了形核基底。当合金中添加1.0%Al-5Ti-1B时,再添加Y会使初生相尺寸进一步减小,形貌规整。当复合添加1.0%Al-5Ti-1B和1.0%Y时,初生Mg_(2)Si相平均尺寸降低到10.2μm,形貌为细小多边形状,合金拉伸力学性能最优,稀土Y的变质机理主要为吸附毒化。
【Purposes】In order to refine the coarse Mg_(2)Si phase in Mg-Al-Si alloy,the Mg-5Al-5Si alloys are modified by adding Al-5Ti-1B and rare earth Y.【Methods】The Mg-Al-Si alloys with different compositions were prepared by smelting.Various means were used to analyze the composition,microstructure,and mechanical properties of alloys before and after modification,and discuss modification mechanism.【Findings】The results show that,adding Al-5Ti-1B to the Mg-5Al-5Si alloy transforms the morphology of the primary phase from coarse bulk to fine dendritic or polygon,the number of eutectic phases decreases with the increase of Al-5Ti-1B,while the hardness of the alloys increases significantly,which is attributed to TiB_(2) phase acting as the heterogeneous nucleation sites for primary Mg_(2)Si phase.On the foundation of adding 1.0%Al-5Ti-1B,rare earth Y can further modify the size and morphology of Mg_(2)Si.When 1.0%Al-5Ti-1B and 1.0%Y are added together,the average size of the primary Mg_(2)Si is decreased to 10.2μm,the morphology of primary Mg_(2)Si is fine polygonal,and the alloy has the best tensile mechanical properties,with the modification mechanism of rare earth Y mainly adsorption and poisoning.
作者
康文旭
马润山
崔泽云
范晋平
KANG Wenxu;MA Runshan;CUI Zeyun;FAN Jinping(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《太原理工大学学报》
CAS
北大核心
2024年第3期474-482,共9页
Journal of Taiyuan University of Technology
基金
太原理工大学技术开发项目(RH19200007)。
