本文主要研究内容
作者张金睿（2019）在《Ti-24Nb-4Zr-8Sn合金损伤容限行为研究》一文中研究指出：Ti-24Nb-4Zr-8Sn(wt.%,简称Ti2448)合金是一种亚稳β型多功能钛合金,利用纳米尺度成分分解调控连续相变,获得了高强度和低模量等良好力学性能以及非线性、超弹性和宽温域可调控热膨胀等优异功能特性,在生物医用、智能器件等领域具有良好的应用前景。前期初步研究结果显示该合金具有良好的高低周疲劳损伤抗力,但其内在影响机制尚不清楚,而且目前金属材料疲劳损伤机制的构建均以线性弹性变形为基础,难以适用于非线弹性材料。因此,本文围绕非线弹性Ti2448合金的损伤容限性能,开展了缺口疲劳、疲劳裂纹扩展以及断裂韧性等方面的研究,并探究与线弹性金属材料的行为差异,期望为非线弹性金属材料疲劳损伤机制的构建奠定基础。热轧态Ti2448合金缺口疲劳行为研究表明:在强度模量比值接近1/50条件下,这种非线弹性合金仍然具有优异的抗缺口疲劳损伤综合性能,突破了金属材料强度与缺口疲劳抗力的倒置关系,合金的疲劳断口呈现出曲折的山峰状形貌,断面起伏可超过样品直径的60%,显著区别于线弹性金属材料的平直断面。合金的疲劳缺口敏感性在同等条件下低于线弹性Ti-6Al-4V合金,结合理论分析及单边切口板状样品的DIC(数字图像相关)实验结果,发现这主要源于其本征的非线弹性变形行为,非线弹性可以有效缓解缺口根部的实际应力集中,而且缓解效果随着外加应力的提高而增强,是一种抑制缺口疲劳损伤的自适应机制。锻造态Ti2448合金的疲劳裂纹扩展行为表现出明显的各向异性,其中R-L取向(径向-轴向)和R-R取向(径向-径向)的疲劳裂纹扩展门槛值随着应力比的提高而逐渐降低,且裂纹在扩展过程中虽然有微观偏折但宏观保持平直,表现出与线弹性金属材料一致的特征。而L-R取向(轴向-径向)的疲劳裂纹明显偏离名义扩展平面,发生宏观尺度的偏折,这种特殊行为主要与以下因素有关:一方面,L-R取向的裂纹闭合程度高于其他两个取向,这会明显降低裂纹尖端的有效驱动力,延缓裂纹向前扩展;另外,三种取向中仅L-R取向在受力方向表现出非线弹性变形行为,使裂纹前沿形成弹性梯度场,可能造成裂纹的宏观偏折。非线弹性更加明显的热轧态Ti2448合金单边切口板状样品在疲劳裂纹扩展过程中发生了更大尺度的裂纹偏折及分叉行为,进一步验证了非线弹性变形对疲劳裂纹扩展的阻滞作用,显著提高了合金的疲劳裂纹扩展寿命,最终表现出优于线弹性Ti-6A1-4V合金和316L不锈钢的疲劳裂纹综合性能。在断裂韧性J-R阻力曲线中的几乎整个有效裂纹扩展阶段,锻造态Ti2448合金J积分韧性值的弹性分量均要高于塑性分量,即使裂纹已经发生了明显扩展,弹性部分仍然占据主导地位,这显著区别于线弹性金属材料中塑性部分主导裂纹扩展韧性的情况,与一些超弹性高分子材料的特征相似,表现出一种特殊的由弹性主导的增韧机制。合金不同取向的裂纹启裂韧性与扩展韧性均存在差异,其中L-R取向表现出优异的裂纹扩展韧性,这主要源于其曲折的粗糙断面吸收了更大的断裂能量。作为一种结构功能一体化材料,非线弹性Ti2448合金的强度与损伤容限综合性能在模量归一化后优于大部分线弹性金属材料。对该合金损伤容限行为的进一步深入研究,不仅有望为金属材料强度与损伤容限性能的倒置关系提供优化方案,更可为非线弹性金属材料力学损伤机制的构建奠定基础。
Abstract
Ti-24Nb-4Zr-8Sn(wt.%,jian chen Ti2448)ge jin shi yi chong ya wen βxing duo gong neng tai ge jin ,li yong na mi che du cheng fen fen jie diao kong lian xu xiang bian ,huo de le gao jiang du he di mo liang deng liang hao li xue xing neng yi ji fei xian xing 、chao dan xing he kuan wen yu ke diao kong re peng zhang deng you yi gong neng te xing ,zai sheng wu yi yong 、zhi neng qi jian deng ling yu ju you liang hao de ying yong qian jing 。qian ji chu bu yan jiu jie guo xian shi gai ge jin ju you liang hao de gao di zhou pi lao sun shang kang li ,dan ji nei zai ying xiang ji zhi shang bu qing chu ,er ju mu qian jin shu cai liao pi lao sun shang ji zhi de gou jian jun yi xian xing dan xing bian xing wei ji chu ,nan yi kuo yong yu fei xian dan xing cai liao 。yin ci ,ben wen wei rao fei xian dan xing Ti2448ge jin de sun shang rong xian xing neng ,kai zhan le que kou pi lao 、pi lao lie wen kuo zhan yi ji duan lie ren xing deng fang mian de yan jiu ,bing tan jiu yu xian dan xing jin shu cai liao de hang wei cha yi ,ji wang wei fei xian dan xing jin shu cai liao pi lao sun shang ji zhi de gou jian dian ding ji chu 。re ga tai Ti2448ge jin que kou pi lao hang wei yan jiu biao ming :zai jiang du mo liang bi zhi jie jin 1/50tiao jian xia ,zhe chong fei xian dan xing ge jin reng ran ju you you yi de kang que kou pi lao sun shang zeng ge xing neng ,tu po le jin shu cai liao jiang du yu que kou pi lao kang li de dao zhi guan ji ,ge jin de pi lao duan kou cheng xian chu qu she de shan feng zhuang xing mao ,duan mian qi fu ke chao guo yang pin zhi jing de 60%,xian zhe ou bie yu xian dan xing jin shu cai liao de ping zhi duan mian 。ge jin de pi lao que kou min gan xing zai tong deng tiao jian xia di yu xian dan xing Ti-6Al-4Vge jin ,jie ge li lun fen xi ji chan bian qie kou ban zhuang yang pin de DIC(shu zi tu xiang xiang guan )shi yan jie guo ,fa xian zhe zhu yao yuan yu ji ben zheng de fei xian dan xing bian xing hang wei ,fei xian dan xing ke yi you xiao huan jie que kou gen bu de shi ji ying li ji zhong ,er ju huan jie xiao guo sui zhao wai jia ying li de di gao er zeng jiang ,shi yi chong yi zhi que kou pi lao sun shang de zi kuo ying ji zhi 。duan zao tai Ti2448ge jin de pi lao lie wen kuo zhan hang wei biao xian chu ming xian de ge xiang yi xing ,ji zhong R-Lqu xiang (jing xiang -zhou xiang )he R-Rqu xiang (jing xiang -jing xiang )de pi lao lie wen kuo zhan men jian zhi sui zhao ying li bi de di gao er zhu jian jiang di ,ju lie wen zai kuo zhan guo cheng zhong sui ran you wei guan pian she dan hong guan bao chi ping zhi ,biao xian chu yu xian dan xing jin shu cai liao yi zhi de te zheng 。er L-Rqu xiang (zhou xiang -jing xiang )de pi lao lie wen ming xian pian li ming yi kuo zhan ping mian ,fa sheng hong guan che du de pian she ,zhe chong te shu hang wei zhu yao yu yi xia yin su you guan :yi fang mian ,L-Rqu xiang de lie wen bi ge cheng du gao yu ji ta liang ge qu xiang ,zhe hui ming xian jiang di lie wen jian duan de you xiao qu dong li ,yan huan lie wen xiang qian kuo zhan ;ling wai ,san chong qu xiang zhong jin L-Rqu xiang zai shou li fang xiang biao xian chu fei xian dan xing bian xing hang wei ,shi lie wen qian yan xing cheng dan xing ti du chang ,ke neng zao cheng lie wen de hong guan pian she 。fei xian dan xing geng jia ming xian de re ga tai Ti2448ge jin chan bian qie kou ban zhuang yang pin zai pi lao lie wen kuo zhan guo cheng zhong fa sheng le geng da che du de lie wen pian she ji fen cha hang wei ,jin yi bu yan zheng le fei xian dan xing bian xing dui pi lao lie wen kuo zhan de zu zhi zuo yong ,xian zhe di gao le ge jin de pi lao lie wen kuo zhan shou ming ,zui zhong biao xian chu you yu xian dan xing Ti-6A1-4Vge jin he 316Lbu xiu gang de pi lao lie wen zeng ge xing neng 。zai duan lie ren xing J-Rzu li qu xian zhong de ji hu zheng ge you xiao lie wen kuo zhan jie duan ,duan zao tai Ti2448ge jin Jji fen ren xing zhi de dan xing fen liang jun yao gao yu su xing fen liang ,ji shi lie wen yi jing fa sheng le ming xian kuo zhan ,dan xing bu fen reng ran zhan ju zhu dao de wei ,zhe xian zhe ou bie yu xian dan xing jin shu cai liao zhong su xing bu fen zhu dao lie wen kuo zhan ren xing de qing kuang ,yu yi xie chao dan xing gao fen zi cai liao de te zheng xiang shi ,biao xian chu yi chong te shu de you dan xing zhu dao de zeng ren ji zhi 。ge jin bu tong qu xiang de lie wen qi lie ren xing yu kuo zhan ren xing jun cun zai cha yi ,ji zhong L-Rqu xiang biao xian chu you yi de lie wen kuo zhan ren xing ,zhe zhu yao yuan yu ji qu she de cu cao duan mian xi shou le geng da de duan lie neng liang 。zuo wei yi chong jie gou gong neng yi ti hua cai liao ,fei xian dan xing Ti2448ge jin de jiang du yu sun shang rong xian zeng ge xing neng zai mo liang gui yi hua hou you yu da bu fen xian dan xing jin shu cai liao 。dui gai ge jin sun shang rong xian hang wei de jin yi bu shen ru yan jiu ,bu jin you wang wei jin shu cai liao jiang du yu sun shang rong xian xing neng de dao zhi guan ji di gong you hua fang an ,geng ke wei fei xian dan xing jin shu cai liao li xue sun shang ji zhi de gou jian dian ding ji chu 。
论文参考文献
论文详细介绍
论文作者分别是来自中国科学技术大学的张金睿，发表于刊物中国科学技术大学2019-07-12论文，是一篇关于金属材料论文,损伤容限论文,缺口疲劳论文,疲劳裂纹扩展论文,断裂韧性论文,中国科学技术大学2019-07-12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，资料来自中国科学技术大学2019-07-12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：金属材料论文; 损伤容限论文; 缺口疲劳论文; 疲劳裂纹扩展论文; 断裂韧性论文; 中国科学技术大学2019-07-12论文;