基于第一性原理的Si/SiC、Al/SiC界面成键特性和结合强度对比研究
Comparative study on bonding characteristics and bonding strengths of Si/SiC and Al/SiC interfaces based on first principles
肖鹏 1胡启耀 1邓昀麒1
作者信息
- 1. 南昌航空大学 航空制造工程学院,南昌 330063
- 折叠
摘要
采用半固态搅拌铸造法制备AlSi7-SiC复合材料,并利用真空压铸工艺实现了其近净成形,结合第一性原理计算方法研究了共晶Si对SiC颗粒和基体界面结合强度的影响.结果显示,在AlSi7-SiC复合材料中,发现较为严重的共晶Si偏析现象,当SiC颗粒同时处于共晶Si和α-Al边界时,形成了少量的共晶Si夹杂、被大量共晶Si包裹、完全被共晶Si包裹三种典型的界面.第一性原理计算结果显示,在C端和Si端的Si/SiC界面中,弛豫后topSi1配位方式具有最大的粘附功,与Al/SiC界面相比,Si/SiC界面具有更高的结合强度.Si偏析相提高了界面处的电荷密度,因而具有更好的界面结构稳定性.
Abstract
AlSi7-SiC composite was prepared by semi-solid stirring casting,and its near-net shape forming was achieved by vacuum die casting.The influence of eutectic Si segregation on the interface strength of SiC-Al composite was studied by the first principles calculation method.The results shown that a mass of eutectic Si seg-regation was found in the matrix of the prepared AlSi7-SiC composites and three typical interfaces were formed:mixed up with a few eutectic Si,a half trapped in eutectic Si and completely trapped in eutectic Si.The calcula-tion results shown that the Si/SiC interface with C-terminated and Si-terminated,the topSi1 coordination mode has the largest adhesion work after relaxation.The interface bonding strength of the Si/SiC interface is greater than that of the Al/SiC interface.Compared with the Al/SiC interface,the Si/SiC interface had a better stability of interface structure attributed to the strong covalent bond formed at the Si/SiC interface and the segregated Si phase improved the interfacial charge density.
关键词
SiC-Al基复合材料/元素偏析/第一性原理/界面性能Key words
SiC Al matrix composites/Element segregation/First principles/Interfacial performance引用本文复制引用
基金项目
江西省自然科学基金(20192BAB20003)
江西省金属材料微观结构控制重点实验室开放基金(EJ201903061)
校级"课程思政"示范课程建设经费(SZ22118)
校级教改课题(JY21026)
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据