本文主要研究内容
作者董金磊(2019)在《内生镧基非晶复合材料在室温及低温动态拉伸下的力学行为》一文中研究指出:块体非晶合金由于长程无序的特殊原子排列使其具有优异的力学及物理性能,已成为材料领域新的研究热点之一。但非晶合金在室温变形中的脆性断裂制约了其在工程领域的应用。非晶复合材料的出现为解决非晶合金室温脆性提供了有效的途径,其中,内生树枝晶增韧的非晶复合材料展现出显著的拉伸塑性,例如钛基、锆基和镧基非晶复合材料等。现代工程领域要求材料在极端的服役条件(例如低温和高应变速率)下具有优异的力学性能,然而非晶复合材料在极端环境下的力学行为研究较少。因此,对非晶复合材料开展室温及低温动态拉伸力学行为的研究具有重要意义。本论文选取La74Al14Cu6Ni6(La74)非晶复合材料作为研究对象,在室温及低温环境下对其进行准静态拉伸与动态拉伸实验,探究温度与应变速率对其力学行为的影响。(1)室温准静态拉伸下,La74非晶复合材料屈服强度为420 MPa,表现出4%的均匀塑性变形。树枝晶内激活变形孪晶,孪晶作为塑性承载者并提供显著的加工硬化能力。室温动态拉伸下,La74非晶复合材料具有2%的拉伸塑性,树枝晶内位错滑移主导塑性变形。随着应变速率的增加,屈服强度逐渐降低,呈现负的应变速率敏感性。负的应变速率敏感性很大程度上依赖于非晶基体在动态拉伸下剧烈的温升效应。(2)低温准静态拉伸下,La74非晶复合材料屈服强度达到550 MPa,拉伸塑性为2%,表现出稳定的加工硬化能力,树枝晶内出现高体积分数的变形孪晶。低温动态拉伸下,La74非晶复合材料展现出较小的塑性变形。低温环境抑制非晶基体中剪切带的温升效应,相比于室温动态拉伸下,屈服强度增加,并且随着应变速率的提高,流动应力下降趋势减缓。通过剪切带韧度理论,分别计算晶体相与非晶基体相的剪切带韧度随应变速率的变化关系,结果表明随着应变速率的提高,两相剪切带韧度差值减小,从而导致非晶复合材料发生韧脆转变。(3)协同剪切模型建立了室温变形下内生非晶复合材料屈服强度随着应变速率的变化关系,Johnson-Cook(J-C)模型描述了室温动态拉伸下非晶复合材料的塑性流动行为,协同剪切模型与J-C模型构建的本构方程很好的预测了La74非晶复合材料的力学行为。
Abstract
kuai ti fei jing ge jin you yu chang cheng mo xu de te shu yuan zi pai lie shi ji ju you you yi de li xue ji wu li xing neng ,yi cheng wei cai liao ling yu xin de yan jiu re dian zhi yi 。dan fei jing ge jin zai shi wen bian xing zhong de cui xing duan lie zhi yao le ji zai gong cheng ling yu de ying yong 。fei jing fu ge cai liao de chu xian wei jie jue fei jing ge jin shi wen cui xing di gong le you xiao de tu jing ,ji zhong ,nei sheng shu zhi jing zeng ren de fei jing fu ge cai liao zhan xian chu xian zhe de la shen su xing ,li ru tai ji 、gao ji he lan ji fei jing fu ge cai liao deng 。xian dai gong cheng ling yu yao qiu cai liao zai ji duan de fu yi tiao jian (li ru di wen he gao ying bian su lv )xia ju you you yi de li xue xing neng ,ran er fei jing fu ge cai liao zai ji duan huan jing xia de li xue hang wei yan jiu jiao shao 。yin ci ,dui fei jing fu ge cai liao kai zhan shi wen ji di wen dong tai la shen li xue hang wei de yan jiu ju you chong yao yi yi 。ben lun wen shua qu La74Al14Cu6Ni6(La74)fei jing fu ge cai liao zuo wei yan jiu dui xiang ,zai shi wen ji di wen huan jing xia dui ji jin hang zhun jing tai la shen yu dong tai la shen shi yan ,tan jiu wen du yu ying bian su lv dui ji li xue hang wei de ying xiang 。(1)shi wen zhun jing tai la shen xia ,La74fei jing fu ge cai liao qu fu jiang du wei 420 MPa,biao xian chu 4%de jun yun su xing bian xing 。shu zhi jing nei ji huo bian xing luan jing ,luan jing zuo wei su xing cheng zai zhe bing di gong xian zhe de jia gong ying hua neng li 。shi wen dong tai la shen xia ,La74fei jing fu ge cai liao ju you 2%de la shen su xing ,shu zhi jing nei wei cuo hua yi zhu dao su xing bian xing 。sui zhao ying bian su lv de zeng jia ,qu fu jiang du zhu jian jiang di ,cheng xian fu de ying bian su lv min gan xing 。fu de ying bian su lv min gan xing hen da cheng du shang yi lai yu fei jing ji ti zai dong tai la shen xia ju lie de wen sheng xiao ying 。(2)di wen zhun jing tai la shen xia ,La74fei jing fu ge cai liao qu fu jiang du da dao 550 MPa,la shen su xing wei 2%,biao xian chu wen ding de jia gong ying hua neng li ,shu zhi jing nei chu xian gao ti ji fen shu de bian xing luan jing 。di wen dong tai la shen xia ,La74fei jing fu ge cai liao zhan xian chu jiao xiao de su xing bian xing 。di wen huan jing yi zhi fei jing ji ti zhong jian qie dai de wen sheng xiao ying ,xiang bi yu shi wen dong tai la shen xia ,qu fu jiang du zeng jia ,bing ju sui zhao ying bian su lv de di gao ,liu dong ying li xia jiang qu shi jian huan 。tong guo jian qie dai ren du li lun ,fen bie ji suan jing ti xiang yu fei jing ji ti xiang de jian qie dai ren du sui ying bian su lv de bian hua guan ji ,jie guo biao ming sui zhao ying bian su lv de di gao ,liang xiang jian qie dai ren du cha zhi jian xiao ,cong er dao zhi fei jing fu ge cai liao fa sheng ren cui zhuai bian 。(3)xie tong jian qie mo xing jian li le shi wen bian xing xia nei sheng fei jing fu ge cai liao qu fu jiang du sui zhao ying bian su lv de bian hua guan ji ,Johnson-Cook(J-C)mo xing miao shu le shi wen dong tai la shen xia fei jing fu ge cai liao de su xing liu dong hang wei ,xie tong jian qie mo xing yu J-Cmo xing gou jian de ben gou fang cheng hen hao de yu ce le La74fei jing fu ge cai liao de li xue hang wei 。
论文参考文献
论文详细介绍
论文作者分别是来自太原理工大学的董金磊,发表于刊物太原理工大学2019-07-26论文,是一篇关于内生镧基非晶复合材料论文,力学行为论文,动态拉伸论文,负的应变速率敏感性论文,本构方程论文,太原理工大学2019-07-26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,资料来自太原理工大学2019-07-26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:内生镧基非晶复合材料论文; 力学行为论文; 动态拉伸论文; 负的应变速率敏感性论文; 本构方程论文; 太原理工大学2019-07-26论文;