本文主要研究内容
作者陈晓宇（2019）在《多元Ti-V-Mn系储氢合金的显微组织与吸放氢性能》一文中研究指出：V基固溶体型储氢合金具有理论储氢量高、室温下快速吸放氢、电化学容量大等优点,成为移动储能装置和镍氢电池负极方面最具潜能的材料之一。具有BCC相和C14 Laves相的Ti-V-Mn系合金的活化性能优异,但储氢量较低,且活化机理和吸放氢机制还缺乏系统深入地研究。本文通过调控晶格参数、相比例和热力学参数,系统地研究了三元Ti-V-Mn合金的储氢性能,建立了成分、显微组织与储氢性能之间的关系;通过微量元素替代优化合金成分,获得活化性能和吸放氢性能俱佳的Ti19Hf4V40Mn35Cr2合金;对铸态合金进行热处理,在保持较快的吸氢动力学基础上,进一步提高合金的吸放氢量,并揭示了微结构对储氢性能的作用机制。改变三元合金Ti-V-Mn的成分,对其显微组织和储氢性能进行研究,结果表明:固定V含量,增加Ti/Mn比例能够增大BCC相晶胞体积,合金的有效储氢量占吸氢量的最大比例出现在电子原子比为5.45左右或晶格常数在3.020?时;随着V含量增加,BCC相增加,储氢量先增加后降低。这是由于BCC相是吸氢相,C14 Laves相是氢原子进入基体内形成氢化物的通道;BCC相增加使得晶格间隙增多,形成大量的氢化物,但是相应的氢原子通道减少,进入基体内部困难,吸氢量会降低。储氢性能最佳的三元合金是Ti23V40Mn37,在293 K下的最大储氢量为3.61 wt.%,303 K下有效储氢量为1.41 wt.%。元素Zr/Hf（放热型）分别微量替代三元合金Ti23V40Mn37中的元素Ti,得到四元合金系Ti23-xZrxV40Mn37（x=0,2,4,6,8,10 at.%）和Ti23-xHfxV40Mn37（x=2,4,6at.%）以提高合金的有效储氢量。结果表明,这两种元素都有利于促进第二相C14Laves相的形成,且使C14相由部分小平面和非小平面界面转变为完全的非小平面界面,BCC相呈枝晶形貌。当Zr的替代量超过6 at.%时,四元合金的等温放氢曲线出现高压平台和低压平台,这是因为合金中同时出现柱状树枝晶结构的BCC相和等轴树枝晶结构的BCC相,等轴树枝晶中氢化物的氢原子易扩散形成高压平台;柱状树枝晶结构的BCC相中氢化物的氢原子扩散慢形成低压平台。元素Hf替代Ti后金属氢化物稳定性增强,合金Ti19Hf4V40Mn37的短期储氢循环稳定性最优:二十次吸放氢循环过程后,合金的有效储氢量（1.82 wt.%）是初始有效储氢量的93.3%。其原因是多次循环后,合金的单氢化物残余量少且晶格畸变程度小。采用元素Cr（吸热型）部分替代四元合金Ti19Hf4V40Mn37中的元素Mn,合金中元素Ti含量分布趋于均匀,且富Cr的四面体间隙的种类增加导致有效储氢量增加,平台滞后效应得到明显改善。在293 K下,铸态合金的最优成分是Ti19Hf4V40Mn35Cr2,其有效放氢量高达2.09 wt.%。BCC相与C14 Laves相两相共存最佳的三元合金成分为Ti23V40Mn37、四元合金成分Ti19Hf4V40Mn37和五元合金成分Ti19Hf4V40Mn35Cr2,对以上合金的活化行为和吸放氢行为进行研究,结果表明元素添加降低合金的表观活化能;合金的吸氢过程由形核长大机制转变为扩散机制,吸氢速率由前期氢化物的形核率控制变为氢原子的扩散速率控制;放氢过程为形核长大机制。元素Hf替代后的多元合金具有大的晶格间隙且对氢原子更大的吸引力的特点。在吸氢过程前期氢原子被金属原子迅速吸引,形成氢化物。相互缠结的位错为氢化物形成后的氢原子扩散提供通道,氢原子扩散系数增大,导致铸态合金Ti19Hf4V40Mn37和Ti19Hf4V40Mn35Cr2的吸放氢速率快。对储氢性能优异的铸态合金Ti19Hf4V40Mn35Cr2进行低温长时淬火热处理,显微组织发生明显变化:BCC相由柱状树枝晶转变为等轴树枝晶,球磨后的BCC相晶粒变小甚至存在纳米晶,增加晶界数量。热处理工艺引起合金的显微组织变化,导致合金的二氢化物比例增加,且纳米晶的出现增加晶界扩散能,有利于氢原子扩散。经Kissinger方程计算得到铸态和热处理保温72h合金的单氢化物（β相）的反应活化能依次是83.30 kJ/mol和66.26 kJ/mol,表明热处理降低单氢化物的稳定性。研究其吸放氢性能并发现,淬火态合金在室温下首次吸氢量达2.02wt.%,相比铸态合金的1.4 wt.%,提高了接近44%;由于BCC相比例的增加,热处理合金室温最大吸氢量增长为3.57 wt.%;室温有效储氢量高达2.34 wt.%,较铸态合金提高了12%。升高温度后,饱和吸氢合金的放氢相转变依次为:FCC→BCT,BCT→BCC,HfV2H3.97→HfV2,HfH2→Hf。
Abstract
Vji gu rong ti xing chu qing ge jin ju you li lun chu qing liang gao 、shi wen xia kuai su xi fang qing 、dian hua xue rong liang da deng you dian ,cheng wei yi dong chu neng zhuang zhi he nie qing dian chi fu ji fang mian zui ju qian neng de cai liao zhi yi 。ju you BCCxiang he C14 Lavesxiang de Ti-V-Mnji ge jin de huo hua xing neng you yi ,dan chu qing liang jiao di ,ju huo hua ji li he xi fang qing ji zhi hai que fa ji tong shen ru de yan jiu 。ben wen tong guo diao kong jing ge can shu 、xiang bi li he re li xue can shu ,ji tong de yan jiu le san yuan Ti-V-Mnge jin de chu qing xing neng ,jian li le cheng fen 、xian wei zu zhi yu chu qing xing neng zhi jian de guan ji ;tong guo wei liang yuan su ti dai you hua ge jin cheng fen ,huo de huo hua xing neng he xi fang qing xing neng ju jia de Ti19Hf4V40Mn35Cr2ge jin ;dui zhu tai ge jin jin hang re chu li ,zai bao chi jiao kuai de xi qing dong li xue ji chu shang ,jin yi bu di gao ge jin de xi fang qing liang ,bing jie shi le wei jie gou dui chu qing xing neng de zuo yong ji zhi 。gai bian san yuan ge jin Ti-V-Mnde cheng fen ,dui ji xian wei zu zhi he chu qing xing neng jin hang yan jiu ,jie guo biao ming :gu ding Vhan liang ,zeng jia Ti/Mnbi li neng gou zeng da BCCxiang jing bao ti ji ,ge jin de you xiao chu qing liang zhan xi qing liang de zui da bi li chu xian zai dian zi yuan zi bi wei 5.45zuo you huo jing ge chang shu zai 3.020?shi ;sui zhao Vhan liang zeng jia ,BCCxiang zeng jia ,chu qing liang xian zeng jia hou jiang di 。zhe shi you yu BCCxiang shi xi qing xiang ,C14 Lavesxiang shi qing yuan zi jin ru ji ti nei xing cheng qing hua wu de tong dao ;BCCxiang zeng jia shi de jing ge jian xi zeng duo ,xing cheng da liang de qing hua wu ,dan shi xiang ying de qing yuan zi tong dao jian shao ,jin ru ji ti nei bu kun nan ,xi qing liang hui jiang di 。chu qing xing neng zui jia de san yuan ge jin shi Ti23V40Mn37,zai 293 Kxia de zui da chu qing liang wei 3.61 wt.%,303 Kxia you xiao chu qing liang wei 1.41 wt.%。yuan su Zr/Hf（fang re xing ）fen bie wei liang ti dai san yuan ge jin Ti23V40Mn37zhong de yuan su Ti,de dao si yuan ge jin ji Ti23-xZrxV40Mn37（x=0,2,4,6,8,10 at.%）he Ti23-xHfxV40Mn37（x=2,4,6at.%）yi di gao ge jin de you xiao chu qing liang 。jie guo biao ming ,zhe liang chong yuan su dou you li yu cu jin di er xiang C14Lavesxiang de xing cheng ,ju shi C14xiang you bu fen xiao ping mian he fei xiao ping mian jie mian zhuai bian wei wan quan de fei xiao ping mian jie mian ,BCCxiang cheng zhi jing xing mao 。dang Zrde ti dai liang chao guo 6 at.%shi ,si yuan ge jin de deng wen fang qing qu xian chu xian gao ya ping tai he di ya ping tai ,zhe shi yin wei ge jin zhong tong shi chu xian zhu zhuang shu zhi jing jie gou de BCCxiang he deng zhou shu zhi jing jie gou de BCCxiang ,deng zhou shu zhi jing zhong qing hua wu de qing yuan zi yi kuo san xing cheng gao ya ping tai ;zhu zhuang shu zhi jing jie gou de BCCxiang zhong qing hua wu de qing yuan zi kuo san man xing cheng di ya ping tai 。yuan su Hfti dai Tihou jin shu qing hua wu wen ding xing zeng jiang ,ge jin Ti19Hf4V40Mn37de duan ji chu qing xun huan wen ding xing zui you :er shi ci xi fang qing xun huan guo cheng hou ,ge jin de you xiao chu qing liang （1.82 wt.%）shi chu shi you xiao chu qing liang de 93.3%。ji yuan yin shi duo ci xun huan hou ,ge jin de chan qing hua wu can yu liang shao ju jing ge ji bian cheng du xiao 。cai yong yuan su Cr（xi re xing ）bu fen ti dai si yuan ge jin Ti19Hf4V40Mn37zhong de yuan su Mn,ge jin zhong yuan su Tihan liang fen bu qu yu jun yun ,ju fu Crde si mian ti jian xi de chong lei zeng jia dao zhi you xiao chu qing liang zeng jia ,ping tai zhi hou xiao ying de dao ming xian gai shan 。zai 293 Kxia ,zhu tai ge jin de zui you cheng fen shi Ti19Hf4V40Mn35Cr2,ji you xiao fang qing liang gao da 2.09 wt.%。BCCxiang yu C14 Lavesxiang liang xiang gong cun zui jia de san yuan ge jin cheng fen wei Ti23V40Mn37、si yuan ge jin cheng fen Ti19Hf4V40Mn37he wu yuan ge jin cheng fen Ti19Hf4V40Mn35Cr2,dui yi shang ge jin de huo hua hang wei he xi fang qing hang wei jin hang yan jiu ,jie guo biao ming yuan su tian jia jiang di ge jin de biao guan huo hua neng ;ge jin de xi qing guo cheng you xing he chang da ji zhi zhuai bian wei kuo san ji zhi ,xi qing su lv you qian ji qing hua wu de xing he lv kong zhi bian wei qing yuan zi de kuo san su lv kong zhi ;fang qing guo cheng wei xing he chang da ji zhi 。yuan su Hfti dai hou de duo yuan ge jin ju you da de jing ge jian xi ju dui qing yuan zi geng da de xi yin li de te dian 。zai xi qing guo cheng qian ji qing yuan zi bei jin shu yuan zi xun su xi yin ,xing cheng qing hua wu 。xiang hu chan jie de wei cuo wei qing hua wu xing cheng hou de qing yuan zi kuo san di gong tong dao ,qing yuan zi kuo san ji shu zeng da ,dao zhi zhu tai ge jin Ti19Hf4V40Mn37he Ti19Hf4V40Mn35Cr2de xi fang qing su lv kuai 。dui chu qing xing neng you yi de zhu tai ge jin Ti19Hf4V40Mn35Cr2jin hang di wen chang shi cui huo re chu li ,xian wei zu zhi fa sheng ming xian bian hua :BCCxiang you zhu zhuang shu zhi jing zhuai bian wei deng zhou shu zhi jing ,qiu mo hou de BCCxiang jing li bian xiao shen zhi cun zai na mi jing ,zeng jia jing jie shu liang 。re chu li gong yi yin qi ge jin de xian wei zu zhi bian hua ,dao zhi ge jin de er qing hua wu bi li zeng jia ,ju na mi jing de chu xian zeng jia jing jie kuo san neng ,you li yu qing yuan zi kuo san 。jing Kissingerfang cheng ji suan de dao zhu tai he re chu li bao wen 72hge jin de chan qing hua wu （βxiang ）de fan ying huo hua neng yi ci shi 83.30 kJ/molhe 66.26 kJ/mol,biao ming re chu li jiang di chan qing hua wu de wen ding xing 。yan jiu ji xi fang qing xing neng bing fa xian ,cui huo tai ge jin zai shi wen xia shou ci xi qing liang da 2.02wt.%,xiang bi zhu tai ge jin de 1.4 wt.%,di gao le jie jin 44%;you yu BCCxiang bi li de zeng jia ,re chu li ge jin shi wen zui da xi qing liang zeng chang wei 3.57 wt.%;shi wen you xiao chu qing liang gao da 2.34 wt.%,jiao zhu tai ge jin di gao le 12%。sheng gao wen du hou ,bao he xi qing ge jin de fang qing xiang zhuai bian yi ci wei :FCC→BCT,BCT→BCC,HfV2H3.97→HfV2,HfH2→Hf。
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论文作者分别是来自哈尔滨工业大学的陈晓宇，发表于刊物哈尔滨工业大学2019-12-07论文，是一篇关于相比例论文,晶格常数论文,活化性能论文,储氢性能论文,热处理论文,哈尔滨工业大学2019-12-07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，资料来自哈尔滨工业大学2019-12-07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：相比例论文; 晶格常数论文; 活化性能论文; 储氢性能论文; 热处理论文; 哈尔滨工业大学2019-12-07论文;