摘要
铝钪合金是制备基于压电效应的射频滤波器镀制氮化铝钪薄膜的关键材料,其中高钪铝合金由于易出现裂纹。故以高钪含量的铝钪合金为研究对象,采用Thermo-Calc软件基于Kou模型计算了背向逆扩散下不同Sc含量的裂纹敏感性指数曲线,并基于计算结果进行了ProCAST模拟仿真,然后用相同工艺下的实验进行了验证。采用扫描电镜(SEM)、金相、电子背散射衍射(EBSD)对高钪铝合金及裂纹进行了表征。实验结果表明,Al-Sc二元合金体系的裂纹敏感性曲线呈现三个峰值;Sc质量分数为47%的铝钪合金在凝固过程中,上表面中心区域先形成液膜,随后向内部继续凝固,外部晶粒为柱状生长;高钪铝合金的热裂纹属于凝固裂纹,其萌生与扩展均始于Al_(3)Sc与Al2Sc相界面交界处和Al_(3)Sc相界面,其主要产生原因为Al_(3)Sc与Al2Sc相性质差异导致的凝固过程中晶粒生长速率不均,可考虑采取加热烘烤模具等方式改善。研究进一步揭示了高钪铝合金凝固过程中晶粒生长与热裂纹的形成过程,为铝钪合金体系热裂纹研究奠定了理论基础。
Aluminum-scandium alloy is a key material for preparing aluminum-scandium nitride films for radio frequency filters based on the piezoelectric effect,among which high-scandium aluminum alloy is prone to cracking.Therefore,by taking the aluminum-scandium alloy with high scandium content as the research object,the crack sensitivity index curves of different Sc contents under backward reverse diffusion were calculated based on the Kou model using the Thermo-Calc software.The ProCAST simulation was carried out based on the calculation results and then verified by experiments under the same process.The high-scandium aluminum alloy and its cracks were characterized by scanning electron microscopy(SEM),metallography,and electron backscatter diffraction(EBSD).The experimental results show that the crack sensitivity curve of the Al-Sc binary alloy system presents three peaks;when the aluminum-scandium alloy with an Sc mass fraction of 47%solidifies,a liquid film is formed in the central area of the upper surface and then continues to solidify inward,with the external grains growing in a columnar pattern.The hot cracks of high-scandium aluminum alloys belong to solidification cracks.Their initiation and propagation both start at the interface between the Al_(3)Sc and Al2Sc phases and the Al_(3)Sc phase interface.The main cause is the uneven grain growth rate during the solidification process due to the difference in the properties of the Al_(3)Sc and Al2Sc phases.Measures such as heating and baking the mold can be considered for improvement.The research further reveals the grain growth and formation process of hot cracks during the solidification of high-scandium aluminum alloy,laying a theoretical foundation for the study of hot cracks in aluminumscandium alloy systems.
作者
黄培
冯岩松
刘华
黄美松
郭利平
蒋子为
周晓
胡雕
Huang Pei;Feng Yansong;Liu Hua;Huang Meisong;Guo Liping;Jiang Ziwei;Zhou Xiao;Hu Diao(Hunan Rare Erath Co.,Ltd.,Changsha Hunan 410126,China;Hunan Key Laboratory for Rare Earth Functional Materials,Changsha Hunan 410126,China;Hunan Rare Earth Metal Materials Research Institute Co.,Ltd.,Changsha Hunan 410126,China)
出处
《硬质合金》
2025年第3期191-198,共8页
Cemented Carbides
基金
国家重点研发计划(2022YFB3504402)
湖南省科技重大专项(2023GK1080)。
