本文主要研究内容
作者郜俊震（2019）在《A201铝合金高固相分数半固态压铸行为与组织性能研究》一文中研究指出：高固相分数半固态压铸在充型过程中浆料流动平稳,能有效减少卷气等压铸缺陷,适合制备对组织性能要求高的结构件产品。本文以一种Al-Cu-Mg-Ag合金——A201高强铝合金为实验材料,研究了二次加热过程中A201铝合金半固态组织的演变规律,采用旋转热焓平衡法设备(Swirl Enthalpy Equilibration Device,SEED),研究了工艺参数对A201铝合金高固相分数流变浆料组织形貌的影响规律,分析了浆料制备过程中的温度场变化及浆料冷却行为,探讨了SEED工艺下球晶组织的形核长大机理,设计了半固态压铸热裂评价模具,研究了 A201铝合金不同半固态压铸工艺下的热裂倾向,最后半固态压铸成形了高端复杂零部件压叶轮。本论文的主要研究内容和结果如下:DSC分析表明,在A201铝合金高固相分数半固态浆料制备过程中,可以适当的通过降低升温或者冷却速率来获得更大的工艺窗口。在二次加热过程中,随着保温时间的延长,A201铝合金坯料固相颗粒形状因子变化不明显,但颗粒持续以体扩散控制的方式长大,根据LSW模型算得晶粒粗化速率为940μm3/s。应用SEED工艺制备了 A201铝合金高固相分数流变浆料。结果表明:在SEED工艺中可以通过适当降低浇注温度,减少旋转冷却时间的方式获得晶粒细小圆整、分布均匀的半固态浆料。在浇注温度为660℃,冷却时间为65s参数下,能够制备出心部和中部初生α-Al晶粒尺寸为68μm,整体较为均匀的A201铝合金高固相分数半固态坯料。系统研究了SEED制浆过程中的熔体冷却行为。制浆过程可以分为两个阶段:激冷阶段和平缓降温阶段。由于坩埚壁的激冷作用,在熔体内部形成三个温度区。三者温差随时间增加而逐渐减小。降低坩埚外壁的传热,可以显著改变浆料内部的温度场分布,减小浆料边部到心部的温差,明显提高了A201铝合金半固态浆料组织均匀性,初生α-Al晶粒更加均匀圆整,边部的枝晶层基本消失。对后续改进SEED制浆坩埚的设计,提高SEED制备浆料的质量提供了实验依据。研究分析了 SEED工艺下晶粒的形核及近球形/球形的生长机制。SEED浆料的晶核主要来源于两个部分:一是低过热度浇注下,熔体在坩埚的激冷作用下形成了大量晶核;二是合金熔体迅速降温到过冷状态下,液相发生了整体形核。在激冷阶段,界面张力对界面稳定性起主导作用,同时熔体中存在较大的温度梯度和较强的对流混合作用,抑制了成分过冷,初生α-Al球晶能维持界面稳定;在弱对流的平缓冷却阶段,在高密度晶粒和低速冷却的条件下,由于晶粒之间浓度场和温度场的叠加,减小了界面前沿的溶度梯度和温度梯度,溶质的分布更为均匀,因此提高了界面稳定性,使初生α-Al能够继续保持球形生长。设计了半固态压铸热裂评价模具,建立了半固态压铸的热裂倾向评价方法。铸造压力越高,A201铝合金试棒的热裂倾向越低,当压力从30MPa增加到90MPa,热裂敏感性指数从38降到0.3,在本研究中,半固态成形组织晶粒保持了近球形和蔷薇颗粒状,液体在压力较低时也能实现有效补缩,热裂倾向降低的最主要原因是增加压力更大的补偿了铸件内部收缩应力。当模具温度从50℃升高到200℃,热裂敏感性指数从35降低到3。验证了高性能铝合金高固相分数半固态成形高端复杂零部件的工程化应用前景。通过提高模具温度,改善了 A201铝合金半固态浆料的对压叶轮叶片的充填能力,同时增加铸造压力可以有效提高A201铝合金半固态压叶轮内部的组织致密性。最后制备出了高质量的A201铝合金压叶轮铸件,相比319s铝合金半固态叶轮和2618铝合金锻造叶轮产品的力学性能更高,经过T71热处理后,屈服强度、抗拉强度和伸长率分别为402MPa、475MPa和7.3%。
Abstract
gao gu xiang fen shu ban gu tai ya zhu zai chong xing guo cheng zhong jiang liao liu dong ping wen ,neng you xiao jian shao juan qi deng ya zhu que xian ,kuo ge zhi bei dui zu zhi xing neng yao qiu gao de jie gou jian chan pin 。ben wen yi yi chong Al-Cu-Mg-Agge jin ——A201gao jiang lv ge jin wei shi yan cai liao ,yan jiu le er ci jia re guo cheng zhong A201lv ge jin ban gu tai zu zhi de yan bian gui lv ,cai yong xuan zhuai re han ping heng fa she bei (Swirl Enthalpy Equilibration Device,SEED),yan jiu le gong yi can shu dui A201lv ge jin gao gu xiang fen shu liu bian jiang liao zu zhi xing mao de ying xiang gui lv ,fen xi le jiang liao zhi bei guo cheng zhong de wen du chang bian hua ji jiang liao leng que hang wei ,tan tao le SEEDgong yi xia qiu jing zu zhi de xing he chang da ji li ,she ji le ban gu tai ya zhu re lie ping jia mo ju ,yan jiu le A201lv ge jin bu tong ban gu tai ya zhu gong yi xia de re lie qing xiang ,zui hou ban gu tai ya zhu cheng xing le gao duan fu za ling bu jian ya xie lun 。ben lun wen de zhu yao yan jiu nei rong he jie guo ru xia :DSCfen xi biao ming ,zai A201lv ge jin gao gu xiang fen shu ban gu tai jiang liao zhi bei guo cheng zhong ,ke yi kuo dang de tong guo jiang di sheng wen huo zhe leng que su lv lai huo de geng da de gong yi chuang kou 。zai er ci jia re guo cheng zhong ,sui zhao bao wen shi jian de yan chang ,A201lv ge jin pi liao gu xiang ke li xing zhuang yin zi bian hua bu ming xian ,dan ke li chi xu yi ti kuo san kong zhi de fang shi chang da ,gen ju LSWmo xing suan de jing li cu hua su lv wei 940μm3/s。ying yong SEEDgong yi zhi bei le A201lv ge jin gao gu xiang fen shu liu bian jiang liao 。jie guo biao ming :zai SEEDgong yi zhong ke yi tong guo kuo dang jiang di jiao zhu wen du ,jian shao xuan zhuai leng que shi jian de fang shi huo de jing li xi xiao yuan zheng 、fen bu jun yun de ban gu tai jiang liao 。zai jiao zhu wen du wei 660℃,leng que shi jian wei 65scan shu xia ,neng gou zhi bei chu xin bu he zhong bu chu sheng α-Aljing li che cun wei 68μm,zheng ti jiao wei jun yun de A201lv ge jin gao gu xiang fen shu ban gu tai pi liao 。ji tong yan jiu le SEEDzhi jiang guo cheng zhong de rong ti leng que hang wei 。zhi jiang guo cheng ke yi fen wei liang ge jie duan :ji leng jie duan he ping huan jiang wen jie duan 。you yu gan guo bi de ji leng zuo yong ,zai rong ti nei bu xing cheng san ge wen du ou 。san zhe wen cha sui shi jian zeng jia er zhu jian jian xiao 。jiang di gan guo wai bi de chuan re ,ke yi xian zhe gai bian jiang liao nei bu de wen du chang fen bu ,jian xiao jiang liao bian bu dao xin bu de wen cha ,ming xian di gao le A201lv ge jin ban gu tai jiang liao zu zhi jun yun xing ,chu sheng α-Aljing li geng jia jun yun yuan zheng ,bian bu de zhi jing ceng ji ben xiao shi 。dui hou xu gai jin SEEDzhi jiang gan guo de she ji ,di gao SEEDzhi bei jiang liao de zhi liang di gong le shi yan yi ju 。yan jiu fen xi le SEEDgong yi xia jing li de xing he ji jin qiu xing /qiu xing de sheng chang ji zhi 。SEEDjiang liao de jing he zhu yao lai yuan yu liang ge bu fen :yi shi di guo re du jiao zhu xia ,rong ti zai gan guo de ji leng zuo yong xia xing cheng le da liang jing he ;er shi ge jin rong ti xun su jiang wen dao guo leng zhuang tai xia ,ye xiang fa sheng le zheng ti xing he 。zai ji leng jie duan ,jie mian zhang li dui jie mian wen ding xing qi zhu dao zuo yong ,tong shi rong ti zhong cun zai jiao da de wen du ti du he jiao jiang de dui liu hun ge zuo yong ,yi zhi le cheng fen guo leng ,chu sheng α-Alqiu jing neng wei chi jie mian wen ding ;zai ruo dui liu de ping huan leng que jie duan ,zai gao mi du jing li he di su leng que de tiao jian xia ,you yu jing li zhi jian nong du chang he wen du chang de die jia ,jian xiao le jie mian qian yan de rong du ti du he wen du ti du ,rong zhi de fen bu geng wei jun yun ,yin ci di gao le jie mian wen ding xing ,shi chu sheng α-Alneng gou ji xu bao chi qiu xing sheng chang 。she ji le ban gu tai ya zhu re lie ping jia mo ju ,jian li le ban gu tai ya zhu de re lie qing xiang ping jia fang fa 。zhu zao ya li yue gao ,A201lv ge jin shi bang de re lie qing xiang yue di ,dang ya li cong 30MPazeng jia dao 90MPa,re lie min gan xing zhi shu cong 38jiang dao 0.3,zai ben yan jiu zhong ,ban gu tai cheng xing zu zhi jing li bao chi le jin qiu xing he qiang wei ke li zhuang ,ye ti zai ya li jiao di shi ye neng shi xian you xiao bu su ,re lie qing xiang jiang di de zui zhu yao yuan yin shi zeng jia ya li geng da de bu chang le zhu jian nei bu shou su ying li 。dang mo ju wen du cong 50℃sheng gao dao 200℃,re lie min gan xing zhi shu cong 35jiang di dao 3。yan zheng le gao xing neng lv ge jin gao gu xiang fen shu ban gu tai cheng xing gao duan fu za ling bu jian de gong cheng hua ying yong qian jing 。tong guo di gao mo ju wen du ,gai shan le A201lv ge jin ban gu tai jiang liao de dui ya xie lun xie pian de chong tian neng li ,tong shi zeng jia zhu zao ya li ke yi you xiao di gao A201lv ge jin ban gu tai ya xie lun nei bu de zu zhi zhi mi xing 。zui hou zhi bei chu le gao zhi liang de A201lv ge jin ya xie lun zhu jian ,xiang bi 319slv ge jin ban gu tai xie lun he 2618lv ge jin duan zao xie lun chan pin de li xue xing neng geng gao ,jing guo T71re chu li hou ,qu fu jiang du 、kang la jiang du he shen chang lv fen bie wei 402MPa、475MPahe 7.3%。
论文参考文献
论文详细介绍
论文作者分别是来自北京科技大学的郜俊震，发表于刊物北京科技大学2019-06-27论文，是一篇关于铝合金论文,高固相分数论文,半固态压铸论文,球晶组织论文,热裂论文,组织性能论文,北京科技大学2019-06-27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，资料来自北京科技大学2019-06-27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：铝合金论文; 高固相分数论文; 半固态压铸论文; 球晶组织论文; 热裂论文; 组织性能论文; 北京科技大学2019-06-27论文;