材料期刊网

采用分子动力学方法和修正的嵌入原子势(MEAM),系统地研究了Mg,Si,Fe 3种元素与Al刃型位错的相互作用.研究结果表明,在铝合金中,Mg,Si,Fe 3种合金元素都易于偏聚到位错周围,且Mg和Si与位错的相互作用强于Fe,展现了更良好的固溶强化效果.另外,为了阐明时效强化时铝合金中元素聚集对材料力学性能的影响,进而研究了不同尺寸的Mg团簇与位错的相互作用,研究发现铝合金中的大尺寸的团簇与位错相互作用更强烈,与位错相互吸引,产生明显的钉扎作用,阻碍位错的运动.本研究从原子尺度分析了铝合金中不同种类元素(Mg,Si,Fe)和不同尺寸的元素团簇与位错的相互作用,阐述了时效过程中合金元素对材料强化的影响,为今后实验和新型铝合金的开发提供了理论指导.

Molecular dynamics simulations with the modified embedded atom method (MEAM) were used to study the interaction between Al edge dislocation and Mg,Si,and Fe dopants in the alloy.The calculated results showed that Mg,Si,Fe atoms tended to gather around the dislocation in the Al alloy.Compared with Fe,the interactions of the edge dislocation with Mg and Si were stronger,so Mg and Si had a better solid solution strengthening effect in this alloy.Furthermore,in order to clarify the influence of alloy elements aggregation on the mechanical properties of aluminum alloys during aging process,the interaction of the dislocation with the Mg clusters was studied.It was found that larger clusters in aluminum alloys had a stronger interaction with the dislocations.The larger cluster could obviously draw the dislocations and inhibited their movement,resulting in a better pinning effect.The present work analyzed the interaction of dislocations with Mg,Si,Fe elements and element clusters with various sizes in aluminum alloys at the atomic scale.Based on these results,we further shed light on the strengthening effects of alloying elements in aluminum alloys during the aging process,which would provide a theoretical guidance for future experiments and the development of new aluminum alloys.