本文主要研究内容
作者刘伟（2019）在《Mg-Gd-Y-Zn系合金时效析出行为的研究》一文中研究指出：课题组设计的EW75(Mg-7Gd-5Y-1Nd-0.5Zr)合金展现了优异的力学性能(抗拉强度450MPa,延伸率5%)。近年来,Mg-rare earth(RE)-Zn系合金中发现长周期(Long Period Stacking Ordered/LPSO)结构相,该相使合金的延伸率提高,塑性增强。于是设计Mg-7Gd-3Y-xNd-1Zn-0.5Zr(x=1、0wt.%)合金,通过均匀化、单级和双级时效等进行组织调控,来实现LPSO结构和β序列多相同时析出,使合金具有优异强度的同时提高延伸率。虽然目前对Mg-RE-Zn系合金组织和性能研究较多,但其时效析出行为还存在争议。本文以此为立题依据,采用扫描和透射电子显微学等技术,研究合金在铸态、均匀化态、单级和双级时效态过程中组织变化和析出相演化。两种铸态合金的组织包含镁基体、网状和块状的共晶相、块状和针状的LPSO结构相。共晶β相(f.c.c.,a=0.74nm),化学组成为(Mg,Zn)3RE;14H-LPSO化学组成为Mg12(RE,Zn)。Nd会抑制14H-LPSO的产生。Nd会降低共晶β相和14H-LPSO结构相的形成温度。经双级均匀化520℃/48h+5 30℃/2h,两种铸态合金过烧。经单级均匀化525C/48h(30℃水淬),两种铸态合金中的β相与14H-LPSO结构相都回溶到基体,只剩点状富Zr/Zn相,对后续单级和双级时效影响不大。研究了单级时效过程中合金的析出行为。经单级均匀化的两种合金在240℃时效,Nd会提高合金的热稳定性。Nd含量为1wt.%的合金经240℃单级时效透射分析结果表明,析出相包含β序列析出相(六角环状有序溶质团簇、之字形GP区、βp’、β’和β1)和γ序列析出相(γ’和14H-LPSO(y))。时效初期析出相为有序溶质团簇、之字形GP区和早期形成的β’。有序溶质团簇和之字形GP区在惯习面{1100}α形成,之字形GP区沿<1010>α有序堆垛形成β’相。峰时效阶段强化析出相主要为β’和βp’。β’为底心正交结构(b.c.o.),晶格常数a=0.64nm,b=2.22nm,c=0.52nm,以{1120}α为惯习面,与基体完全共格,其结构模型为Mg7RE,空间形貌为凸透镜状。βp’相是β’相的前驱体,其结构有待进一步研究。过时效阶段析出相主要为β’、β1、γ’、14H-LPSO(y)。β1(f.c.c.,a=0.74nm),由(β’相转变而来,以{1010}α为惯习面,与基体不共格,结构模型为Mg3X。γ’是亚稳的LPSO结构相,将会转变成14H-LPSO。γ’与基体完全共格,其堆垛顺序为“ABCA”。该合金优异的热稳定性归功于γ’和14H-LPSO阻碍β’和β1沿[0001]α。的生长,同时也可能与RE低的扩散速率或者β’和β1两相的形貌尺寸因素有关。研究了双级时效过程中合金的析出行为。单级均匀化的两种合金经500℃/2h第一级时效,两种合金的组织主要为晶界上块状β(Mg5(RE,Zn))相和晶内针状14H-LPSO(Mg12(RE,Zn))结构相。Nd含量为1wt.%的合金经500℃C/2h+240℃C第二级时效透射电镜分析结果表明,析出相包含β序列析出相(ββ’、β’、β’F和β1)和γ序列析出相(γ’和14H-LPSO)。时效初期析出相为早期形成的β’。峰时效阶段强化析出相主要为β’、βp’和14H-LPSO。过时效阶段析出相主要为β’、β’F、β1、γ’、14H-LPSO。ββ’、p’、β1、γ’和14H-LPSO的晶体学特征与单级时效的析出相一致。桥接结构β’F相(b.c.o.),晶格常数a=0.64nm,b=1.14nm,c=0.52nm,与基体完全共格,是由β’粗化转变而来,同时也是β1相容易形核的部位。β’F向β1的转变是通过简单的原子替代和结构松弛。经双级长时间时效稀土Nd与Zn在β1和LPSO结构中开始富集。
Abstract
ke ti zu she ji de EW75(Mg-7Gd-5Y-1Nd-0.5Zr)ge jin zhan xian le you yi de li xue xing neng (kang la jiang du 450MPa,yan shen lv 5%)。jin nian lai ,Mg-rare earth(RE)-Znji ge jin zhong fa xian chang zhou ji (Long Period Stacking Ordered/LPSO)jie gou xiang ,gai xiang shi ge jin de yan shen lv di gao ,su xing zeng jiang 。yu shi she ji Mg-7Gd-3Y-xNd-1Zn-0.5Zr(x=1、0wt.%)ge jin ,tong guo jun yun hua 、chan ji he shuang ji shi xiao deng jin hang zu zhi diao kong ,lai shi xian LPSOjie gou he βxu lie duo xiang tong shi xi chu ,shi ge jin ju you you yi jiang du de tong shi di gao yan shen lv 。sui ran mu qian dui Mg-RE-Znji ge jin zu zhi he xing neng yan jiu jiao duo ,dan ji shi xiao xi chu hang wei hai cun zai zheng yi 。ben wen yi ci wei li ti yi ju ,cai yong sao miao he tou she dian zi xian wei xue deng ji shu ,yan jiu ge jin zai zhu tai 、jun yun hua tai 、chan ji he shuang ji shi xiao tai guo cheng zhong zu zhi bian hua he xi chu xiang yan hua 。liang chong zhu tai ge jin de zu zhi bao han mei ji ti 、wang zhuang he kuai zhuang de gong jing xiang 、kuai zhuang he zhen zhuang de LPSOjie gou xiang 。gong jing βxiang (f.c.c.,a=0.74nm),hua xue zu cheng wei (Mg,Zn)3RE;14H-LPSOhua xue zu cheng wei Mg12(RE,Zn)。Ndhui yi zhi 14H-LPSOde chan sheng 。Ndhui jiang di gong jing βxiang he 14H-LPSOjie gou xiang de xing cheng wen du 。jing shuang ji jun yun hua 520℃/48h+5 30℃/2h,liang chong zhu tai ge jin guo shao 。jing chan ji jun yun hua 525C/48h(30℃shui cui ),liang chong zhu tai ge jin zhong de βxiang yu 14H-LPSOjie gou xiang dou hui rong dao ji ti ,zhi sheng dian zhuang fu Zr/Znxiang ,dui hou xu chan ji he shuang ji shi xiao ying xiang bu da 。yan jiu le chan ji shi xiao guo cheng zhong ge jin de xi chu hang wei 。jing chan ji jun yun hua de liang chong ge jin zai 240℃shi xiao ,Ndhui di gao ge jin de re wen ding xing 。Ndhan liang wei 1wt.%de ge jin jing 240℃chan ji shi xiao tou she fen xi jie guo biao ming ,xi chu xiang bao han βxu lie xi chu xiang (liu jiao huan zhuang you xu rong zhi tuan cu 、zhi zi xing GPou 、βp’、β’he β1)he γxu lie xi chu xiang (γ’he 14H-LPSO(y))。shi xiao chu ji xi chu xiang wei you xu rong zhi tuan cu 、zhi zi xing GPou he zao ji xing cheng de β’。you xu rong zhi tuan cu he zhi zi xing GPou zai guan xi mian {1100}αxing cheng ,zhi zi xing GPou yan <1010>αyou xu dui duo xing cheng β’xiang 。feng shi xiao jie duan jiang hua xi chu xiang zhu yao wei β’he βp’。β’wei de xin zheng jiao jie gou (b.c.o.),jing ge chang shu a=0.64nm,b=2.22nm,c=0.52nm,yi {1120}αwei guan xi mian ,yu ji ti wan quan gong ge ,ji jie gou mo xing wei Mg7RE,kong jian xing mao wei tu tou jing zhuang 。βp’xiang shi β’xiang de qian qu ti ,ji jie gou you dai jin yi bu yan jiu 。guo shi xiao jie duan xi chu xiang zhu yao wei β’、β1、γ’、14H-LPSO(y)。β1(f.c.c.,a=0.74nm),you (β’xiang zhuai bian er lai ,yi {1010}αwei guan xi mian ,yu ji ti bu gong ge ,jie gou mo xing wei Mg3X。γ’shi ya wen de LPSOjie gou xiang ,jiang hui zhuai bian cheng 14H-LPSO。γ’yu ji ti wan quan gong ge ,ji dui duo shun xu wei “ABCA”。gai ge jin you yi de re wen ding xing gui gong yu γ’he 14H-LPSOzu ai β’he β1yan [0001]α。de sheng chang ,tong shi ye ke neng yu REdi de kuo san su lv huo zhe β’he β1liang xiang de xing mao che cun yin su you guan 。yan jiu le shuang ji shi xiao guo cheng zhong ge jin de xi chu hang wei 。chan ji jun yun hua de liang chong ge jin jing 500℃/2hdi yi ji shi xiao ,liang chong ge jin de zu zhi zhu yao wei jing jie shang kuai zhuang β(Mg5(RE,Zn))xiang he jing nei zhen zhuang 14H-LPSO(Mg12(RE,Zn))jie gou xiang 。Ndhan liang wei 1wt.%de ge jin jing 500℃C/2h+240℃Cdi er ji shi xiao tou she dian jing fen xi jie guo biao ming ,xi chu xiang bao han βxu lie xi chu xiang (ββ’、β’、β’Fhe β1)he γxu lie xi chu xiang (γ’he 14H-LPSO)。shi xiao chu ji xi chu xiang wei zao ji xing cheng de β’。feng shi xiao jie duan jiang hua xi chu xiang zhu yao wei β’、βp’he 14H-LPSO。guo shi xiao jie duan xi chu xiang zhu yao wei β’、β’F、β1、γ’、14H-LPSO。ββ’、p’、β1、γ’he 14H-LPSOde jing ti xue te zheng yu chan ji shi xiao de xi chu xiang yi zhi 。qiao jie jie gou β’Fxiang (b.c.o.),jing ge chang shu a=0.64nm,b=1.14nm,c=0.52nm,yu ji ti wan quan gong ge ,shi you β’cu hua zhuai bian er lai ,tong shi ye shi β1xiang rong yi xing he de bu wei 。β’Fxiang β1de zhuai bian shi tong guo jian chan de yuan zi ti dai he jie gou song chi 。jing shuang ji chang shi jian shi xiao xi tu Ndyu Znzai β1he LPSOjie gou zhong kai shi fu ji 。
论文参考文献
论文详细介绍
论文作者分别是来自北京有色金属研究总院的刘伟，发表于刊物北京有色金属研究总院2019-07-10论文，是一篇关于稀土镁合金论文,时效论文,析出相论文,结构相论文,北京有色金属研究总院2019-07-10论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自北京有色金属研究总院2019-07-10论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：稀土镁合金论文; 时效论文; 析出相论文; 结构相论文; 北京有色金属研究总院2019-07-10论文;