双峰基面织构对Mg-2.6Nd-0.55Zn-0.5Zr合金弯曲应力及显微组织演变的影响  

Effects of bimodal basal texture on bending stress and microstructure evolution of Mg−2.6Nd−0.55Zn−0.5Zr alloys

作　　者：张文丛[1] 刘宇轩 马俊飞[1] 王文珂[1] 陈文振[1] 刘欣彤 杨建雷[1] Wen-cong ZHANG;Yu-xuan LIU;Jun-fei MA;Wen-ke WANG;Wen-zhen CHEN;Xin-tong LIU;Jian-lei YANG(School of Materials Science and Engineering,Harbin Institute of Technology at Weihai,Weihai 264209,China)

机构地区：[1]哈尔滨工业大学(威海)材料科学与工程学院,威海264209

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第3期714-727,共14页中国有色金属学报（英文版）

基　　金：supported by National Natural Science Foundation of China(Nos.51975146,52205344);the Natural Science Foundation of Shandong Province,China(No.ZR2020QE171);the Key Research and Development Plan in Shandong Province,China(No.2019JZZY010364);the National Defense Basic Scientific Research of China(No.JCK2018603C017)。

摘　　要：沿Mg-2.6Nd-0.55Zn-0.5Zr板材挤压方向(ED)和横向(TD)分别切取试样,研究双峰基面织构对其弯曲应力及显微组织演变的影响。结果显示,具有弱基面织构的ED试样比TD试样的弯曲应力低很多。这种各向异性是不同织构状态对变形机制及显微组织演变的作用所导致的。对于具有弱基面织构的ED试样,其主要的变形机制是基面滑移:内侧区域存在少量的{10■2}拉伸孪生,而外侧区域则是基面滑移和柱面滑移。相比之下,具有强基面织构的TD试样在内侧区域激活更多的{10■2}拉伸孪生,在外侧区域激活更多的柱面滑移。{10■2}拉伸孪生的激活一方面促使<0002>//压缩方向类型的织构增加,使内侧区域的织构角度限制在±30°范围内,另一方面减少高位错密度和低角度晶界的出现几率。{10■2}拉伸孪生的大量激活使TD试样保持高应变硬化能力,是该试样具有较高弯曲应力的根本原因。The extrusion direction(ED)and transverse direction(TD)samples were cut from Mg−2.6Nd−0.55Zn−0.5Zr alloy sheet,and the effects of bimodal basal texture on the bending stress and microstructure evolution were investigated.Results showed that the ED sample with weak basal texture possessed much lower bending stress than the TD sample.This anisotropy is attributed to the role of different textures on the evolution of deformation mechanisms and microstructures.For the ED sample with weak basal texture,the dominant deformation mechanisms were basal slip in the majority with minor supplement of{10■2}tension twin in the inner region while basal slip and prismatic slip in the outer region.In comparison,the TD sample with strong basal texture activated more{10■2}tension twin in the inner region and more prismatic slip in the outer region.The activation of{10■2}tension twin promoted the development of<0002>//compression direction type texture with the confined±30°angle range in the inner region and reduced the emergence propensity of high dislocation density and low angle grain boundaries.The massive activation of{10■2}tension twin allowed the TD sample to maintain a high strain-hardening capacity,which was the fundamental reason for the high bending stress in this sample.

关 键 词：Mg-Nd-Zn-Zr合金 织构 拉伸孪生 三点弯曲 弯曲应力 显微组织演变 

分 类 号：TG146.22[一般工业技术—材料科学与工程]