Cu-Al层状复合材料金属间化合物结构稳定性的第一性原理计算  

First-principles calculation of structural stability of intermetallic compounds in Cu-Al layered composites

作　　者：李爽 王文焱[1,2] 张飞扬 崔云峰 谢敬佩 王爱琴[1,2] 朱晓龙 高铭[1,2] LI Shuang;WANG Wen-yan;ZHANG Fei-yang;CUI Yun-feng;XIE Jing-pei;WANG Ai-qin;ZHU Xiao-long;GAO Ming(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Luoyang 471023,China;Digital Molding Engineering Research Center of Tungsten and Molybdenum Materials in Henan Province,Luoyang 471822,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]有色金属新材料与先进加工技术省部共建协同创新中心,河南洛阳471023 [3]河南省钨钼材料数字成型工程研究中心,河南洛阳471822

出　　处：《材料热处理学报》2024年第9期65-76,共12页Transactions of Materials and Heat Treatment

基　　金：国家重点研发计划(2021YFB3701300)。

摘　　要：铜铝层状复合材料在固液复合铸轧成型时,固态铜与液态铝在接触面发生界面反应生成的金属间化合物容易引发晶界脆性、晶间裂纹或弹性畸变致使其开裂而失效。因此,一个强而稳定的界面对于整个复合材料的结构强度至关重要。为深入了解界面金属间化合物的化学键合、晶体结构及稳定性,利用第一性原理对Cu-Al层状复合材料中常见的金属间化合物Al_(4)Cu_(9)、Al_(2)Cu、AlCu开展了热力学性能、力学性能和电子结构的相关计算。有效生成热数值表明,扩散初始阶段Al_(2)Cu相将在界面处最先生成,待Al_(2)Cu初生相形成后,将依次生成Al_(4)Cu_(9)、AlCu。Al_(2)Cu、Al_(4)Cu_(9)和AlCu均符合力学稳定性标准,对比它们的B/G值、泊松比和硬度,3种金属间化合物均为脆性相,其中Al_(2)Cu的脆性最大且硬度最高。通过对能带、态密度和Mulliken布居进行分析,发现金属键在Al_(2)Cu和AlCu化学键中具有更强的离子性特征,而在Al_(4)Cu_(9)化学键中具有更强的共价性特征,使得Al和Cu原子之间的相互作用更紧密,稳定性更强。When copper-aluminum layered composites are formed by solid-liquid composite casting and rolling,the intermetallic compounds generated by the interface reaction between solid copper and liquid aluminum at the contact surface are prone to cause grain boundary brittleness,intergranular cracks,or elastic distortion,leading to cracking and failure of the composites.Therefore,a strong and stable interface is crucial for the structural strength of the entire composites.To gain a deeper understanding of the chemical bonding,crystal structure,and stability of intermetallic compounds at the interface,first-principles calculations were conducted on the thermodynamic properties,mechanical properties,and electronic structure of common intermetallic compounds(Al_(4)Cu_(9),Al_(2)Cu and AlCu)in Cu-Al layered composites.The calculated effective thermodynamic values indicate that the the Al_(2)Cu phase will first form at the interface during the initial diffusion stage,and then Al_(4)Cu_(9) and AlCu will be sequentially generated after the formation of the initial Al_(2)Cu phase.Al_(2)Cu,Al_(4)Cu_(9) and AlCu all meet the criteria for mechanical stability.Comparing their B/G values,Poisson’s ratio and hardness,all three intermetallic compounds are brittle phases,with Al_(2)Cu having the highest brittleness and hardness.By analyzing the band structure,density of states and Mulliken population,it is found that metal bonds have stronger ionic characteristics in Al_(2)Cu and AlCu chemical bonds,while they have stronger covalent characteristics in Al_(4)Cu_(9) chemical bonds,resulting in a closer interaction between Al and Cu atoms and more stable.

关 键 词：Cu-Al层状复合材料 生成焓 结合能 电子结构 力学性能 

分 类 号：TB331[一般工业技术—材料科学与工程]