本文主要研究内容
作者咬登治（2019）在《激光熔覆Inconel 718合金数值模拟研究》一文中研究指出：Inconel 718合金具有抗氧化、抗辐射、抗疲劳、耐腐蚀、焊接性良好等特点,用途广泛,无论直接作为高温零部件还是作为涂层合金它均表现出了优异的性能,是使用量最大的镍基高温合金。激光熔覆技术作为二次修复、表面改性技术的一种,具有清洁、高效、对基材影响小的特点,所以本文以激光熔覆718合金为研究对象,针对718合金对普通合金的表面改性以及718合金零件的修复再制造展开研究。由于激光熔覆快熔快凝、局部高热的特性所以在激光熔覆后会产生很大的应力以及变形,因此研究激光熔覆过程中的温度以及应力尤为重要,而由于熔覆过程的复杂性,很难通过实验的方法对温度和应力的分布、变化进行研究,借用计算机技术,对激光熔覆进行数值模拟,是国内外工作者的热门研究课题,并且得到了越来越广泛的应用。本文应用ANSYS软件,采取模拟与实验结合的方法,建立了718合金预置粉末激光熔覆有限元模型,针对激光熔覆718合金表面改性的工艺参数优化及激光熔覆718合金修复再制造:单道激光熔覆温度场应力场及不同厚度薄壁件单道激光熔覆温度场应力场、温度场对熔覆层凝固的影响、多道搭接激光熔覆温度场应力场,以期为激光熔覆表面改性的工艺优化以及激光熔覆修复再制造提供理论依据。研究成果有:针对激光熔覆718合金的表面改性:通过温度场研究工艺参数对熔覆层质量的影响规律,并最终确定了最优参数。温度场研究结果表明:随着离焦量的增大,熔池最高温度变低,成形系数越来越大而稀释率越来越小,成形效果越来越好;随着扫描速度变大,熔池最高温度变低,同时成形系数变大而稀释率越低,成形越来越好;随着激光功率的变大,熔池最高温度越来越大,成形系数越来越小而稀释率越大,成形效果变差;最优工艺参数-离焦量15mm,扫描速度2mm/s,激光功率1300W。针对激光熔覆修复再制造718合金:对单道激光熔覆718合金温度场及应力场进行模拟分后。温度场结果显示:温度变化曲线可以很好的揭示激光熔覆快熔快凝的特性以及解释板材末端发生烧蚀的原因。应力场结果显示:激光熔覆后,应力主要集中于熔覆层中,等效应力数值大于屈服极限1125MPa,4mm薄板会发生明显变形,但熔覆层中基本不存在裂纹;截面处不同自定义路径上的分应力数值显示,熔覆层部位的纵向应力SZ都为拉应力,横向应力SX较为复杂,厚度方向分应力SY数值很小。通过不同厚度薄壁件温度场应力场的数值模拟可知,基材厚度对激光熔覆718合金过程中的温度场存在较为明显的影响,随着基材厚度变大,熔池最高温度降低,热影响区尺寸变小,且成形系数变高;激光熔覆端部效应越不明显;仅从温度场数值可以得到8mm板材的加工性能优于其他厚度。从应力场数值可知,同种工艺,不同厚度薄壁件的熔覆应力差别较小;在熔覆层部位,薄板的厚度越大,等效应力数值越大;随着板材厚度的增加,熔覆层中的纵向拉应力SZ越来越大;在远离熔覆层的薄板上,厚度越大等效应力数值越小;预热对于减小激光熔覆的残余应力是极为有效的,预热后的变形量明显减小。利用单道激光熔覆的温度场模拟结果得到冷却速度以及温度梯度,最终获得温度场对熔覆层凝固情况即微观组织、元素、性能的影响规律。结果表明:从熔覆层底部到熔覆层顶部,冷却速度越来越快,温度梯度越来越小,结晶速度越来越大;在结晶速度与温度梯度的共同作用下,熔覆层底部到熔覆层顶部的晶粒生长呈现从胞状—柱状树枝晶—等轴晶的变化规律;从熔覆层底部到熔覆层顶部,随着冷却速度的增加,Laves相的析出量越来越小;冷却速度越快,Nb的偏析越小,SR越小,但总体远大于1;在熔覆层部位不同区域的显微硬度数值变化不大。通过对再制造多道搭接激光熔覆过程中的温度场和应力场的模拟。发现:熔覆层道与道之间温度影响明显,前一道会对后一道进行一定的预热,致使后一道的最高温度以及基板的最低温度都升高;应力最大部位处于熔覆层的搭接区域,应力数值大于1280MPa,而熔覆层中的应力数值约在1100-1280MPa之间,大于材料常温时的屈服极限,所以板材会发生明显的变形,裂纹在搭接区域出现的概率要大于熔覆层中;搭接区域横向拉应力SX较大,熔覆层部位纵向拉应力SZ较大;后道熔覆层的熔覆会明显减小前道熔覆层中的等效应力,隔道以后减弱效果会减小;通过6道熔覆层的熔覆,这种减弱效果会导致熔覆层中应力数值呈现由下而上的阶梯式变化。
Abstract
Inconel 718ge jin ju you kang yang hua 、kang fu she 、kang pi lao 、nai fu shi 、han jie xing liang hao deng te dian ,yong tu an fan ,mo lun zhi jie zuo wei gao wen ling bu jian hai shi zuo wei tu ceng ge jin ta jun biao xian chu le you yi de xing neng ,shi shi yong liang zui da de nie ji gao wen ge jin 。ji guang rong fu ji shu zuo wei er ci xiu fu 、biao mian gai xing ji shu de yi chong ,ju you qing jie 、gao xiao 、dui ji cai ying xiang xiao de te dian ,suo yi ben wen yi ji guang rong fu 718ge jin wei yan jiu dui xiang ,zhen dui 718ge jin dui pu tong ge jin de biao mian gai xing yi ji 718ge jin ling jian de xiu fu zai zhi zao zhan kai yan jiu 。you yu ji guang rong fu kuai rong kuai ning 、ju bu gao re de te xing suo yi zai ji guang rong fu hou hui chan sheng hen da de ying li yi ji bian xing ,yin ci yan jiu ji guang rong fu guo cheng zhong de wen du yi ji ying li you wei chong yao ,er you yu rong fu guo cheng de fu za xing ,hen nan tong guo shi yan de fang fa dui wen du he ying li de fen bu 、bian hua jin hang yan jiu ,jie yong ji suan ji ji shu ,dui ji guang rong fu jin hang shu zhi mo ni ,shi guo nei wai gong zuo zhe de re men yan jiu ke ti ,bing ju de dao le yue lai yue an fan de ying yong 。ben wen ying yong ANSYSruan jian ,cai qu mo ni yu shi yan jie ge de fang fa ,jian li le 718ge jin yu zhi fen mo ji guang rong fu you xian yuan mo xing ,zhen dui ji guang rong fu 718ge jin biao mian gai xing de gong yi can shu you hua ji ji guang rong fu 718ge jin xiu fu zai zhi zao :chan dao ji guang rong fu wen du chang ying li chang ji bu tong hou du bao bi jian chan dao ji guang rong fu wen du chang ying li chang 、wen du chang dui rong fu ceng ning gu de ying xiang 、duo dao da jie ji guang rong fu wen du chang ying li chang ,yi ji wei ji guang rong fu biao mian gai xing de gong yi you hua yi ji ji guang rong fu xiu fu zai zhi zao di gong li lun yi ju 。yan jiu cheng guo you :zhen dui ji guang rong fu 718ge jin de biao mian gai xing :tong guo wen du chang yan jiu gong yi can shu dui rong fu ceng zhi liang de ying xiang gui lv ,bing zui zhong que ding le zui you can shu 。wen du chang yan jiu jie guo biao ming :sui zhao li jiao liang de zeng da ,rong chi zui gao wen du bian di ,cheng xing ji shu yue lai yue da er xi shi lv yue lai yue xiao ,cheng xing xiao guo yue lai yue hao ;sui zhao sao miao su du bian da ,rong chi zui gao wen du bian di ,tong shi cheng xing ji shu bian da er xi shi lv yue di ,cheng xing yue lai yue hao ;sui zhao ji guang gong lv de bian da ,rong chi zui gao wen du yue lai yue da ,cheng xing ji shu yue lai yue xiao er xi shi lv yue da ,cheng xing xiao guo bian cha ;zui you gong yi can shu -li jiao liang 15mm,sao miao su du 2mm/s,ji guang gong lv 1300W。zhen dui ji guang rong fu xiu fu zai zhi zao 718ge jin :dui chan dao ji guang rong fu 718ge jin wen du chang ji ying li chang jin hang mo ni fen hou 。wen du chang jie guo xian shi :wen du bian hua qu xian ke yi hen hao de jie shi ji guang rong fu kuai rong kuai ning de te xing yi ji jie shi ban cai mo duan fa sheng shao shi de yuan yin 。ying li chang jie guo xian shi :ji guang rong fu hou ,ying li zhu yao ji zhong yu rong fu ceng zhong ,deng xiao ying li shu zhi da yu qu fu ji xian 1125MPa,4mmbao ban hui fa sheng ming xian bian xing ,dan rong fu ceng zhong ji ben bu cun zai lie wen ;jie mian chu bu tong zi ding yi lu jing shang de fen ying li shu zhi xian shi ,rong fu ceng bu wei de zong xiang ying li SZdou wei la ying li ,heng xiang ying li SXjiao wei fu za ,hou du fang xiang fen ying li SYshu zhi hen xiao 。tong guo bu tong hou du bao bi jian wen du chang ying li chang de shu zhi mo ni ke zhi ,ji cai hou du dui ji guang rong fu 718ge jin guo cheng zhong de wen du chang cun zai jiao wei ming xian de ying xiang ,sui zhao ji cai hou du bian da ,rong chi zui gao wen du jiang di ,re ying xiang ou che cun bian xiao ,ju cheng xing ji shu bian gao ;ji guang rong fu duan bu xiao ying yue bu ming xian ;jin cong wen du chang shu zhi ke yi de dao 8mmban cai de jia gong xing neng you yu ji ta hou du 。cong ying li chang shu zhi ke zhi ,tong chong gong yi ,bu tong hou du bao bi jian de rong fu ying li cha bie jiao xiao ;zai rong fu ceng bu wei ,bao ban de hou du yue da ,deng xiao ying li shu zhi yue da ;sui zhao ban cai hou du de zeng jia ,rong fu ceng zhong de zong xiang la ying li SZyue lai yue da ;zai yuan li rong fu ceng de bao ban shang ,hou du yue da deng xiao ying li shu zhi yue xiao ;yu re dui yu jian xiao ji guang rong fu de can yu ying li shi ji wei you xiao de ,yu re hou de bian xing liang ming xian jian xiao 。li yong chan dao ji guang rong fu de wen du chang mo ni jie guo de dao leng que su du yi ji wen du ti du ,zui zhong huo de wen du chang dui rong fu ceng ning gu qing kuang ji wei guan zu zhi 、yuan su 、xing neng de ying xiang gui lv 。jie guo biao ming :cong rong fu ceng de bu dao rong fu ceng ding bu ,leng que su du yue lai yue kuai ,wen du ti du yue lai yue xiao ,jie jing su du yue lai yue da ;zai jie jing su du yu wen du ti du de gong tong zuo yong xia ,rong fu ceng de bu dao rong fu ceng ding bu de jing li sheng chang cheng xian cong bao zhuang —zhu zhuang shu zhi jing —deng zhou jing de bian hua gui lv ;cong rong fu ceng de bu dao rong fu ceng ding bu ,sui zhao leng que su du de zeng jia ,Lavesxiang de xi chu liang yue lai yue xiao ;leng que su du yue kuai ,Nbde pian xi yue xiao ,SRyue xiao ,dan zong ti yuan da yu 1;zai rong fu ceng bu wei bu tong ou yu de xian wei ying du shu zhi bian hua bu da 。tong guo dui zai zhi zao duo dao da jie ji guang rong fu guo cheng zhong de wen du chang he ying li chang de mo ni 。fa xian :rong fu ceng dao yu dao zhi jian wen du ying xiang ming xian ,qian yi dao hui dui hou yi dao jin hang yi ding de yu re ,zhi shi hou yi dao de zui gao wen du yi ji ji ban de zui di wen du dou sheng gao ;ying li zui da bu wei chu yu rong fu ceng de da jie ou yu ,ying li shu zhi da yu 1280MPa,er rong fu ceng zhong de ying li shu zhi yao zai 1100-1280MPazhi jian ,da yu cai liao chang wen shi de qu fu ji xian ,suo yi ban cai hui fa sheng ming xian de bian xing ,lie wen zai da jie ou yu chu xian de gai lv yao da yu rong fu ceng zhong ;da jie ou yu heng xiang la ying li SXjiao da ,rong fu ceng bu wei zong xiang la ying li SZjiao da ;hou dao rong fu ceng de rong fu hui ming xian jian xiao qian dao rong fu ceng zhong de deng xiao ying li ,ge dao yi hou jian ruo xiao guo hui jian xiao ;tong guo 6dao rong fu ceng de rong fu ,zhe chong jian ruo xiao guo hui dao zhi rong fu ceng zhong ying li shu zhi cheng xian you xia er shang de jie ti shi bian hua 。
论文参考文献
论文详细介绍
论文作者分别是来自兰州理工大学的咬登治，发表于刊物兰州理工大学2019-07-18论文，是一篇关于激光熔覆论文,合金论文,有限元论文,温度场论文,应力场论文,单道论文,凝固论文,多道论文,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：激光熔覆论文; 合金论文; 有限元论文; 温度场论文; 应力场论文; 单道论文; 凝固论文; 多道论文; 兰州理工大学2019-07-18论文;