本文主要研究内容
作者刘强（2019）在《循环载荷和单轴拉伸下纳米铜/铝双层膜孔洞演化的分子动力学研究》一文中研究指出：纳米铜/铝薄膜具有良好的耐腐蚀性、优良的导电导热性和高强度等性能而被人们青睐,其在微纳机电系统中具有广泛的应用前景。在铜/铝异种金属连接或服役期间常出现孔洞缺陷,孔洞缺陷对材料的性能影响较为严重,另外孔洞的生长和聚集会造成裂纹的萌发进而导致材料过早的断裂失效。因此,对纳米铜/铝薄膜内部孔洞的研究,有助于纳米铜/铝薄膜优良性能在实际应用中得到更好的发挥。本文主要应用分子动力学方法研究了纳米铜/铝薄膜在循环载荷下孔洞的形核、生长和闭合演化规律。对比研究不含孔洞与含孔洞纳米铜/铝双层膜在单轴拉伸条件下孔洞生长至材料断裂失效的演化过程。同时,也研究了不同尺寸的孔洞对纳米铜/铝双层膜力学性能的影响。得出以下主要结论:(1)在应变幅比为R=-1的循环载荷条件下对纳米铜/铝双层薄膜进行循环加载模拟实验:研究结果表明孔洞主要有孔洞Ⅰ和孔洞Ⅱ两种形核演化方式,且两种孔洞主要在纳米铜/铝双层薄膜铝侧内部形核。孔洞Ⅰ是在应变加载之前,铜铝原子相互扩散形成双层膜时,由柯肯达尔效应所产生出的空隙缺陷而引发的形核,这种形核方式下,空隙缺陷形成空位后,空位可以在铝侧OTHER结构内部发生位置的相对移动,其向铜原子数相对密集的区域移动,当空位聚集形成孔洞时,便在固定位置生长扩大,此时周围铜原子则有向孔洞位置聚集的趋势。孔洞Ⅱ是由压杆位错被克服所形成的空隙缺陷而引发的形核,这种孔洞形核后在铝侧没有位置的相对移动,直接在原固定位置成长。与孔洞Ⅰ相比,在应变加载过程中,孔洞Ⅱ形核所需应力大、孔洞生长速度较快且尺寸稍大,在应变卸载阶段孔洞闭合速度也较快。(2)在循环载荷下,两种孔洞在形核、生长和闭合过程中有两方面的共同特点,两种孔洞都是在铝侧OTHER结构内部的空隙缺陷处形核,两种孔洞在其生长、闭合过程中外形变化相同。在孔洞生长阶段,两种孔洞在外形上都是先沿应变加载方向拉伸长大,然后沿与应变加载相垂直的方向长大,最后孔洞趋向球形发展。在孔洞闭合阶段,两种孔洞在外形上首先沿应变加载方向压缩成椭球状,然后沿与应变加载相垂直的方向由孔洞两端向孔洞中心闭合消失。另外,在随后的循环加载过程中,孔洞消失位置处没有再次出现新孔洞,而是在铝侧其它位置的OTHER结构内部的空隙缺陷处形核。(3)对含孔洞和不含孔洞的纳米铜/铝双层膜进行单轴拉伸对比:研究发现不含孔洞的纳米铜/铝双层膜应力达到最大抗拉强度时,孔洞在铝侧OTHER结构空隙缺陷区域形核,其附近位错的形核、发射使得孔洞尺寸增加。含孔洞的纳米铜/铝薄膜应力达到屈服强度时,孔洞所在界面位置首先有位错的形核和发射。孔洞在生长过程中向铝侧扩展,铜侧孔洞尺寸则随应变增加有所减小,最终孔洞在铝侧扩展至材料边界进而导致纳米铜/铝薄膜断裂失效。两者共同特点是孔洞在{111}面层错作用下扩展长大,另外,孔洞在生长扩大到材料断裂失效过程中,都是先沿应变拉伸的方向向铝侧扩展,最后沿与应变拉伸相垂直的方向扩展到薄膜边界。(4)对含不同尺寸孔洞的纳米铜/铝双层膜进行单轴拉伸研究:结果显示含不同尺寸孔洞的纳米铜/铝双层膜具有相似的弹性阶段,但在塑性变形阶段,孔洞尺寸小于1.45nm的纳米铜/铝双层膜具有较复杂的流变应力。另外,纳米铜/铝薄膜的弹性模量、屈服强度及抗拉强度都随孔洞尺寸的增加逐渐减小。
Abstract
na mi tong /lv bao mo ju you liang hao de nai fu shi xing 、you liang de dao dian dao re xing he gao jiang du deng xing neng er bei ren men qing lai ,ji zai wei na ji dian ji tong zhong ju you an fan de ying yong qian jing 。zai tong /lv yi chong jin shu lian jie huo fu yi ji jian chang chu xian kong dong que xian ,kong dong que xian dui cai liao de xing neng ying xiang jiao wei yan chong ,ling wai kong dong de sheng chang he ju ji hui zao cheng lie wen de meng fa jin er dao zhi cai liao guo zao de duan lie shi xiao 。yin ci ,dui na mi tong /lv bao mo nei bu kong dong de yan jiu ,you zhu yu na mi tong /lv bao mo you liang xing neng zai shi ji ying yong zhong de dao geng hao de fa hui 。ben wen zhu yao ying yong fen zi dong li xue fang fa yan jiu le na mi tong /lv bao mo zai xun huan zai he xia kong dong de xing he 、sheng chang he bi ge yan hua gui lv 。dui bi yan jiu bu han kong dong yu han kong dong na mi tong /lv shuang ceng mo zai chan zhou la shen tiao jian xia kong dong sheng chang zhi cai liao duan lie shi xiao de yan hua guo cheng 。tong shi ,ye yan jiu le bu tong che cun de kong dong dui na mi tong /lv shuang ceng mo li xue xing neng de ying xiang 。de chu yi xia zhu yao jie lun :(1)zai ying bian fu bi wei R=-1de xun huan zai he tiao jian xia dui na mi tong /lv shuang ceng bao mo jin hang xun huan jia zai mo ni shi yan :yan jiu jie guo biao ming kong dong zhu yao you kong dong Ⅰhe kong dong Ⅱliang chong xing he yan hua fang shi ,ju liang chong kong dong zhu yao zai na mi tong /lv shuang ceng bao mo lv ce nei bu xing he 。kong dong Ⅰshi zai ying bian jia zai zhi qian ,tong lv yuan zi xiang hu kuo san xing cheng shuang ceng mo shi ,you ke ken da er xiao ying suo chan sheng chu de kong xi que xian er yin fa de xing he ,zhe chong xing he fang shi xia ,kong xi que xian xing cheng kong wei hou ,kong wei ke yi zai lv ce OTHERjie gou nei bu fa sheng wei zhi de xiang dui yi dong ,ji xiang tong yuan zi shu xiang dui mi ji de ou yu yi dong ,dang kong wei ju ji xing cheng kong dong shi ,bian zai gu ding wei zhi sheng chang kuo da ,ci shi zhou wei tong yuan zi ze you xiang kong dong wei zhi ju ji de qu shi 。kong dong Ⅱshi you ya gan wei cuo bei ke fu suo xing cheng de kong xi que xian er yin fa de xing he ,zhe chong kong dong xing he hou zai lv ce mei you wei zhi de xiang dui yi dong ,zhi jie zai yuan gu ding wei zhi cheng chang 。yu kong dong Ⅰxiang bi ,zai ying bian jia zai guo cheng zhong ,kong dong Ⅱxing he suo xu ying li da 、kong dong sheng chang su du jiao kuai ju che cun shao da ,zai ying bian xie zai jie duan kong dong bi ge su du ye jiao kuai 。(2)zai xun huan zai he xia ,liang chong kong dong zai xing he 、sheng chang he bi ge guo cheng zhong you liang fang mian de gong tong te dian ,liang chong kong dong dou shi zai lv ce OTHERjie gou nei bu de kong xi que xian chu xing he ,liang chong kong dong zai ji sheng chang 、bi ge guo cheng zhong wai xing bian hua xiang tong 。zai kong dong sheng chang jie duan ,liang chong kong dong zai wai xing shang dou shi xian yan ying bian jia zai fang xiang la shen chang da ,ran hou yan yu ying bian jia zai xiang chui zhi de fang xiang chang da ,zui hou kong dong qu xiang qiu xing fa zhan 。zai kong dong bi ge jie duan ,liang chong kong dong zai wai xing shang shou xian yan ying bian jia zai fang xiang ya su cheng tuo qiu zhuang ,ran hou yan yu ying bian jia zai xiang chui zhi de fang xiang you kong dong liang duan xiang kong dong zhong xin bi ge xiao shi 。ling wai ,zai sui hou de xun huan jia zai guo cheng zhong ,kong dong xiao shi wei zhi chu mei you zai ci chu xian xin kong dong ,er shi zai lv ce ji ta wei zhi de OTHERjie gou nei bu de kong xi que xian chu xing he 。(3)dui han kong dong he bu han kong dong de na mi tong /lv shuang ceng mo jin hang chan zhou la shen dui bi :yan jiu fa xian bu han kong dong de na mi tong /lv shuang ceng mo ying li da dao zui da kang la jiang du shi ,kong dong zai lv ce OTHERjie gou kong xi que xian ou yu xing he ,ji fu jin wei cuo de xing he 、fa she shi de kong dong che cun zeng jia 。han kong dong de na mi tong /lv bao mo ying li da dao qu fu jiang du shi ,kong dong suo zai jie mian wei zhi shou xian you wei cuo de xing he he fa she 。kong dong zai sheng chang guo cheng zhong xiang lv ce kuo zhan ,tong ce kong dong che cun ze sui ying bian zeng jia you suo jian xiao ,zui zhong kong dong zai lv ce kuo zhan zhi cai liao bian jie jin er dao zhi na mi tong /lv bao mo duan lie shi xiao 。liang zhe gong tong te dian shi kong dong zai {111}mian ceng cuo zuo yong xia kuo zhan chang da ,ling wai ,kong dong zai sheng chang kuo da dao cai liao duan lie shi xiao guo cheng zhong ,dou shi xian yan ying bian la shen de fang xiang xiang lv ce kuo zhan ,zui hou yan yu ying bian la shen xiang chui zhi de fang xiang kuo zhan dao bao mo bian jie 。(4)dui han bu tong che cun kong dong de na mi tong /lv shuang ceng mo jin hang chan zhou la shen yan jiu :jie guo xian shi han bu tong che cun kong dong de na mi tong /lv shuang ceng mo ju you xiang shi de dan xing jie duan ,dan zai su xing bian xing jie duan ,kong dong che cun xiao yu 1.45nmde na mi tong /lv shuang ceng mo ju you jiao fu za de liu bian ying li 。ling wai ,na mi tong /lv bao mo de dan xing mo liang 、qu fu jiang du ji kang la jiang du dou sui kong dong che cun de zeng jia zhu jian jian xiao 。
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论文作者分别是来自郑州大学的刘强，发表于刊物郑州大学2019-07-03论文，是一篇关于分子动力学论文,铝薄膜论文,循环载荷论文,孔洞论文,郑州大学2019-07-03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，资料来自郑州大学2019-07-03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：分子动力学论文; 铝薄膜论文; 循环载荷论文; 孔洞论文; 郑州大学2019-07-03论文;