热处理对高压铸造Al-10Si-0.5Mn-0.3Mg合金梯度结构和变形行为的影响  

The influence of heat treatment on the heterogenous structure and deformation behavior of a high pressure die-cast Al-10Si-0.5Mn-0.3Mg alloy

作　　者：夏利红 郑江 刘瑜[2] 宋江凤 蒋斌 XIA LiHong;ZHENG Jiang;LIU Yu;SONG JiangFeng;JIANG Bin(Chongqing Municipal Key Laboratory of Mechanism Design and Control for Manufacturing Equipment,Chongqing Technology and Business University,Chongqing 400067,China;National Engineering Research Centre for Magnesium Alloys,Chongqing University,Chongqing 400044,China;National Key Laboratory of Advanced Casting Technologies,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆工商大学智能装备绿色设计与制造重庆市重点实验室,重庆400067 [2]重庆大学国家镁合金材料工程技术研究中心,重庆400044 [3]重庆大学高端装备铸造技术全国重点实验室,重庆400044

出　　处：《中国科学:技术科学》2025年第4期617-629,共13页Scientia Sinica(Technologica)

基　　金：国家自然科学基金(批准号:51575068,51501023)资助项目。

摘　　要：高压铸造Al-10Si-0.5Mn-0.3Mg合金中的珊瑚状共晶Si在晶界连续分布,形成网络结构,会引起应力集中,诱发裂纹,降低塑性.热处理是将珊瑚状共晶Si转变为球状和棒状,打破网络结构,提升塑性的有效途径.本研究聚焦于T7热处理对高压铸造Al-10Si-0.5Mn-0.3Mg合金微观组织和变形行为的影响.研究结果表明:高压铸造Al-10Si-0.5Mn-0.3Mg合金的微观组织为三明治结构,即包含细晶表层和双峰组织中间层.经过T7处理后,珊瑚状共晶Si颗粒转变为球状和棒状.T7处理并未显著改善变形均匀性,铸态和热处理样品均表现出明显的不均匀变形.与表层相比,中间层的不均匀变形更加显著.然而,T7处理改变了断裂模式,即将脆性断裂转变为韧性断裂.转变共晶Si形貌,打破其网络结构,降低应力集中是断裂模式转变和塑性显著提升的主要原因.The network of coralloid-shaped eutectic Si particles in a high-pressure die-cast Al-10Si-0.5Mn-0.3Mg alloy can lead to stress concentration and induce cracking during deformation,resulting in reduced ductility.To enhance ductility,a crucial step involves transforming these coralloid-like Si particles into globular forms through heat treatment.This study focuses on investigating the effects of T7 heat treatment on the microstructure and deformation behavior of high-pressure die-cast Al-10Si-0.5Mn-0.3Mn alloy.The findings reveal that the high-pressure die-cast Al-10Si-0.5Mn-0.3Mg alloy displays a sandwich microstructure,comprising two skins enveloping a core.After T7 treatment,the coralloid-like eutectic Si particles undergo transformation into globular and rodshaped structures.However,T7 treatment does not lead to a significant improvement in deformation homogeneity,as both the as-cast and heat-treated samples exhibit apparent deformation heterogeneity.Notably,the core displays more pronounced inhomogeneous deformation compared to the skin.Despite the observed reduction in strength after T7 treatment,a noteworthy improvement in ductility is observed.The spheroidization of eutectic Si particles is identified as a primary factor contributing to the shift in cracking mode and the enhancement of ductility.

关 键 词：AL-SI合金 高压铸造 梯度结构 变形不均匀性 塑性 

分 类 号：TG146.21[一般工业技术—材料科学与工程]