摘要
铝合金中不同富铁相对力学性能的影响一直是研究热点,但原位分析不同富铁相在受力过程中的变形行为则较为空白。使用0.5wt%Mn变质了A380铝合金,得到了鱼骨状α-Fe、块状α-Fe以及针状β-Fe共存的A380-0.5Mn合金。通过原位拉伸结合DIC(数字图像相关法)分析研究其受力过程中的组织变形行为,并结合断口分析总结了不同富铁相的变形机理。结果表明,鱼骨状α-Fe及周围基体均存在较小应变,位错运动为切过机制,可提高强塑性。块状α-Fe无明显应变,周围存在微应变,位错运动为绕过机制,可提高强度。平行拉伸方向的针状β-Fe及周围基体均存在较大应变,受力产生内部微裂纹,形成的新相界恶化性能;垂直拉伸方向的针状β-Fe应变较小,周围基体均存在较大应变,是由于位错塞积,产生应力集中导致开裂。
The influence of different iron-rich phases on the mechanical properties of aluminium alloys has been a hot topic of research,but in situ analysis of the deformation behavior of different iron-rich phases during stressing is relatively blank.The A380 aluminum alloy was modified by using 0.5wt%Mn.The A380-0.5Mn alloys with fishboneα-Fe,bulkα-Fe and needle-likeβ-Fe were obtained.The microstructure deformation behavior during the stress process was studied by in situ tensile analysis combined with DIC(digital image correlation method),and the deformation mechanism of different Fe-rich phases was summarized by fracture analysis.The results show that there is a small strain in both the fishboneα-Fe and the surrounding matrix,and the dislocation movement is a cut-through mechanism,which can improve the strength and plasticity.The bulkα-Fe has no obvious strain and there is micro-strain around it,and the dislocation motion is a bypassing mechanism,which can improve the strength.The needle-shapedβ-Fe in the parallel tensile direction and the surrounding matrix all have large strains,which produce internal micro-cracks and deteriorate the properties by forming new phase boundaries;the needle-shapedβ-Fe in the perpendicular tensile direction has small strains and the surrounding matrix has large strains,which are due to dislocation accumulation and stress concentration leading to cracking.
作者
周佳宇
项肇
张栗颖
吴开阳
ZHOU Jiayu;XIANG Zhao;ZHANG Liying;WU Kaiyang(Military Representative Office of the Naval Equipment Department in Wuhan and Jiujiang,Ruichang 332209,China)
出处
《热加工工艺》
北大核心
2023年第24期38-44,共7页
Hot Working Technology
关键词
富铁相
原位拉伸
变形行为
断裂机理
Fe-rich phase
in-situ tensile
deformation behavior
fracture mechanism