本文主要研究内容
作者汪佐瑾（2019）在《AlCoCrFeNi2.1高熵合金断裂机理及轧制改性研究》一文中研究指出：高熵合金（High Entropy Alloy,HEA）作为一种新兴多主元合金,凭借其优异的综合性能,受到广泛的关注。不同于传统合金由一种或两种主元构成,通过添加其他元素来提高性能,高熵合金由五种或五种以上的元素以等原子比或近似等原子比组成,虽然高熵合金由多种主元组成,但它却没有形成吉布斯相率所预测的复杂的金属间化合物,而是形成了简单结构,例如体心立方、面心立方或者是密排六方。已有的研究表明面心立方结构拥有良好的塑性,而体心立方结构可以提供较高的强度,为了能够得到强度和塑性的平衡,人们提出了共晶高熵合金的概念,通过形成面心立方和体心立方共晶相,使合金拥有较高强度的同时,保持良好的塑性。本文通过宏观拉伸、原位拉伸等实验,配合扫描电子显微镜、X射线衍射仪等实验设备和仪器对AlCoCrFeNi2.1共晶高熵合金的力学性能和断裂机理进行了研究。结果表明由面心立方相和体心立方相以层片状方式形成的铸态AlCoCrFeNi2.1共晶高熵合金拥有较高的抗拉强度和良好的断裂塑性,其断裂强度和断裂应变分别达到了1005MPa和15.4%。为了研究共晶高熵合金在单轴拉伸载荷下的断裂机理,本文分别制备了大圆弧试样和小圆弧缺口试样进行原位拉伸实验,结果表明:铸态AlCoCrFeNi2.1共晶高熵合金在受到单轴拉伸载荷时,软韧的面心立方相会先发生塑性变形,形成滑移带,此时与面心立方相紧密结合的体心立方相内部会因为难以发生塑性变形而形成较大的内应力,由于体心立方与面心立方共晶相的界面结合强度要高于体心立方相自身的强度,所以形成的内应力会以体心立方相的断裂来进行释放,并形成一条微裂纹,该初始微裂纹与拉应力方向成45°角,在微裂纹尖端由于尖端效应,会形成较高的应力场,在高应力的作用下裂纹开始扩展,与此同时在尖端附近的体心立方相也会在高应力的作用下形成新的微裂纹,新的裂纹扩展后与原始微裂纹汇集,形成一个主裂纹,随后在主裂纹尖端附近又形成微裂纹,扩展后再次与主裂纹汇集,使主裂纹向前扩展一定距离,这一过程不断进行,直至最终试样断裂。虽然实验过程中发现材料中有夹杂相的开裂和富Al相和基体脱粘现象,但这些地方均没有成为最终形成裂纹的起裂源。对铸态AlCoCrFeNi2.1共晶高熵合金力学性能的研究表明它具有良好的综合力学性能,但考虑到铸态合金中硬脆的体心立方相以粗大的层片状形式存在,限制了合金性能的提高,本文制定了800℃、1000℃和1200℃三个轧制温度对铸态合金进行轧制实验。通过对不同温度轧制材料进行力学性能实验,X射线衍射实验,组织分析实验等相关实验后发现,经轧制后材料的抗拉强度和断裂应变均得到提高,其中经800℃轧制后的性能最佳,抗拉强度和断裂应变分别达到了1475MPa和20.4%,较铸态分别提高了46.8%和32.5%;1200℃轧制后的断裂应变是最高的,达到了25.1%,抗拉强度为1193MPa;1000℃轧制后的性能最差,抗拉强度和断裂应变分别为1085MPa和18.6%。对轧制材料的XRD分析结果显示,经不同温度轧制后,体心立方晶格衍射峰强度降低,部分面心立方晶格衍射峰强度增强,表明轧制后体心立方相得到细化。对轧制面和轧制侧面的SEM和OM观察结果表明,800℃轧制后,体心立方相中的白色颗粒状析出相得到细化,较铸态时的数量也增多;经1000℃轧制后,在材料的轧制面上局部出现了大块体心立方相,白色颗粒状析出相也仅存在于这些体心立方相上,且尺寸明显增大,而在轧制侧面却没有出现白色析出相,而是在面心立方基体上析出了棒状和球状的析出相,该析出相与体心立方共晶相拥有相同的成分和结构;1200℃轧制后的高熵合金,在轧制面和轧制侧面均没有出现白色析出相,在轧制侧面只出现了球状体心立方析出相。综上所述,不同温度的热轧工艺会对AlCoCrFeNi2.1共晶高熵合金的力学性能和相组成产生影响。
Abstract
gao shang ge jin （High Entropy Alloy,HEA）zuo wei yi chong xin xing duo zhu yuan ge jin ,ping jie ji you yi de zeng ge xing neng ,shou dao an fan de guan zhu 。bu tong yu chuan tong ge jin you yi chong huo liang chong zhu yuan gou cheng ,tong guo tian jia ji ta yuan su lai di gao xing neng ,gao shang ge jin you wu chong huo wu chong yi shang de yuan su yi deng yuan zi bi huo jin shi deng yuan zi bi zu cheng ,sui ran gao shang ge jin you duo chong zhu yuan zu cheng ,dan ta que mei you xing cheng ji bu si xiang lv suo yu ce de fu za de jin shu jian hua ge wu ,er shi xing cheng le jian chan jie gou ,li ru ti xin li fang 、mian xin li fang huo zhe shi mi pai liu fang 。yi you de yan jiu biao ming mian xin li fang jie gou yong you liang hao de su xing ,er ti xin li fang jie gou ke yi di gong jiao gao de jiang du ,wei le neng gou de dao jiang du he su xing de ping heng ,ren men di chu le gong jing gao shang ge jin de gai nian ,tong guo xing cheng mian xin li fang he ti xin li fang gong jing xiang ,shi ge jin yong you jiao gao jiang du de tong shi ,bao chi liang hao de su xing 。ben wen tong guo hong guan la shen 、yuan wei la shen deng shi yan ,pei ge sao miao dian zi xian wei jing 、Xshe xian yan she yi deng shi yan she bei he yi qi dui AlCoCrFeNi2.1gong jing gao shang ge jin de li xue xing neng he duan lie ji li jin hang le yan jiu 。jie guo biao ming you mian xin li fang xiang he ti xin li fang xiang yi ceng pian zhuang fang shi xing cheng de zhu tai AlCoCrFeNi2.1gong jing gao shang ge jin yong you jiao gao de kang la jiang du he liang hao de duan lie su xing ,ji duan lie jiang du he duan lie ying bian fen bie da dao le 1005MPahe 15.4%。wei le yan jiu gong jing gao shang ge jin zai chan zhou la shen zai he xia de duan lie ji li ,ben wen fen bie zhi bei le da yuan hu shi yang he xiao yuan hu que kou shi yang jin hang yuan wei la shen shi yan ,jie guo biao ming :zhu tai AlCoCrFeNi2.1gong jing gao shang ge jin zai shou dao chan zhou la shen zai he shi ,ruan ren de mian xin li fang xiang hui xian fa sheng su xing bian xing ,xing cheng hua yi dai ,ci shi yu mian xin li fang xiang jin mi jie ge de ti xin li fang xiang nei bu hui yin wei nan yi fa sheng su xing bian xing er xing cheng jiao da de nei ying li ,you yu ti xin li fang yu mian xin li fang gong jing xiang de jie mian jie ge jiang du yao gao yu ti xin li fang xiang zi shen de jiang du ,suo yi xing cheng de nei ying li hui yi ti xin li fang xiang de duan lie lai jin hang shi fang ,bing xing cheng yi tiao wei lie wen ,gai chu shi wei lie wen yu la ying li fang xiang cheng 45°jiao ,zai wei lie wen jian duan you yu jian duan xiao ying ,hui xing cheng jiao gao de ying li chang ,zai gao ying li de zuo yong xia lie wen kai shi kuo zhan ,yu ci tong shi zai jian duan fu jin de ti xin li fang xiang ye hui zai gao ying li de zuo yong xia xing cheng xin de wei lie wen ,xin de lie wen kuo zhan hou yu yuan shi wei lie wen hui ji ,xing cheng yi ge zhu lie wen ,sui hou zai zhu lie wen jian duan fu jin you xing cheng wei lie wen ,kuo zhan hou zai ci yu zhu lie wen hui ji ,shi zhu lie wen xiang qian kuo zhan yi ding ju li ,zhe yi guo cheng bu duan jin hang ,zhi zhi zui zhong shi yang duan lie 。sui ran shi yan guo cheng zhong fa xian cai liao zhong you ga za xiang de kai lie he fu Alxiang he ji ti tuo nian xian xiang ,dan zhe xie de fang jun mei you cheng wei zui zhong xing cheng lie wen de qi lie yuan 。dui zhu tai AlCoCrFeNi2.1gong jing gao shang ge jin li xue xing neng de yan jiu biao ming ta ju you liang hao de zeng ge li xue xing neng ,dan kao lv dao zhu tai ge jin zhong ying cui de ti xin li fang xiang yi cu da de ceng pian zhuang xing shi cun zai ,xian zhi le ge jin xing neng de di gao ,ben wen zhi ding le 800℃、1000℃he 1200℃san ge ga zhi wen du dui zhu tai ge jin jin hang ga zhi shi yan 。tong guo dui bu tong wen du ga zhi cai liao jin hang li xue xing neng shi yan ,Xshe xian yan she shi yan ,zu zhi fen xi shi yan deng xiang guan shi yan hou fa xian ,jing ga zhi hou cai liao de kang la jiang du he duan lie ying bian jun de dao di gao ,ji zhong jing 800℃ga zhi hou de xing neng zui jia ,kang la jiang du he duan lie ying bian fen bie da dao le 1475MPahe 20.4%,jiao zhu tai fen bie di gao le 46.8%he 32.5%;1200℃ga zhi hou de duan lie ying bian shi zui gao de ,da dao le 25.1%,kang la jiang du wei 1193MPa;1000℃ga zhi hou de xing neng zui cha ,kang la jiang du he duan lie ying bian fen bie wei 1085MPahe 18.6%。dui ga zhi cai liao de XRDfen xi jie guo xian shi ,jing bu tong wen du ga zhi hou ,ti xin li fang jing ge yan she feng jiang du jiang di ,bu fen mian xin li fang jing ge yan she feng jiang du zeng jiang ,biao ming ga zhi hou ti xin li fang xiang de dao xi hua 。dui ga zhi mian he ga zhi ce mian de SEMhe OMguan cha jie guo biao ming ,800℃ga zhi hou ,ti xin li fang xiang zhong de bai se ke li zhuang xi chu xiang de dao xi hua ,jiao zhu tai shi de shu liang ye zeng duo ;jing 1000℃ga zhi hou ,zai cai liao de ga zhi mian shang ju bu chu xian le da kuai ti xin li fang xiang ,bai se ke li zhuang xi chu xiang ye jin cun zai yu zhe xie ti xin li fang xiang shang ,ju che cun ming xian zeng da ,er zai ga zhi ce mian que mei you chu xian bai se xi chu xiang ,er shi zai mian xin li fang ji ti shang xi chu le bang zhuang he qiu zhuang de xi chu xiang ,gai xi chu xiang yu ti xin li fang gong jing xiang yong you xiang tong de cheng fen he jie gou ;1200℃ga zhi hou de gao shang ge jin ,zai ga zhi mian he ga zhi ce mian jun mei you chu xian bai se xi chu xiang ,zai ga zhi ce mian zhi chu xian le qiu zhuang ti xin li fang xi chu xiang 。zeng shang suo shu ,bu tong wen du de re ga gong yi hui dui AlCoCrFeNi2.1gong jing gao shang ge jin de li xue xing neng he xiang zu cheng chan sheng ying xiang 。
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论文作者分别是来自兰州理工大学的汪佐瑾，发表于刊物兰州理工大学2019-07-18论文，是一篇关于共晶高熵合金论文,断裂论文,轧制论文,兰州理工大学2019-07-18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，资料来自兰州理工大学2019-07-18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：共晶高熵合金论文; 断裂论文; 轧制论文; 兰州理工大学2019-07-18论文;