本文主要研究内容
作者张学拯(2019)在《热处理对粉末触变成形SiC_p/6061Al基复合材料组织和力学性能的影响及其强韧化机理研究》一文中研究指出:本文采用一种全新的颗粒增强铝基复合材料制备技术—粉末触变成形技术(PTF),制备了SiC颗粒(SiCp)增强6061铝(PTF-SiCp/6061Al)基复合材料。首先研究了PTF-SiCp/6061Al基复合材料在制备态下的组织和力学性能间的关系,通过与PTF技术制备6061(PTF-6061)合金和金属型铸造(PMC)技术制备6061(PMC-6061)合金对比,澄清了PTF的工艺特点和复合材料的性能优势。接着,研究了热处理对该复合材料组织和力学性能的影响,发现固溶处理可以同时提高复合材料的拉伸强度和延伸率,人工时效处理可以使复合材料产生明显的时效硬化。通过建模计算,揭露了复合材料在固溶处理过程中的强化、韧化机理,以及时效强化机理。研究结果表明:1.相比于传统的PMC技术,PTF工艺能够极大地提高材料的致密度、细化晶粒和共晶组织。PTF复合材料制备态的显微组织是由SiCp、近球状的初生α-Al相(平均尺寸为16.51μm)和晶间二次凝固组织组成;而PMC合金组织则由粗大的等轴晶(90.01μm)和晶间网状的共晶组织构成。由于SiCp对α-Al相的强化作用,复合材料的抗拉强度和屈服强度分别为230MPa和128MPa,显著高于PTF-6061合金和PMC-6061合金。2.在560℃经过6h固溶处理后,复合材料中的共晶组织基本溶解;由于SiC/Al界面阻碍热传递以及SiCp对晶界的钉扎作用,复合材料的组织粗化速率较慢,其整体固溶进程要慢于PTF-6061合金;其抗拉强度、屈服强度和延伸率达到峰值,分别为276 MPa、214 MPa和7%,较制备态分别提升了20.0%、67.2%和169.2%。3.在固溶处理过程中,固溶强化对复合材料屈服强度的贡献值最大,细晶强化、热错配强化和几何必须位错强化对复合材料屈服强度的贡献值中等且相当,Orowan强化对复合材料屈服强度的贡献值甚微,主要是SiCp微米级的尺度和其较大的颗粒间距所致;通过结合各强化机理和SiCp的失效情况而建立的修正剪切滞后模型,较好地预测了该复合材料在固溶过程中的屈服强度;复合材料在固溶过程中的韧化机理为:(1)SiCp的尺寸较小(平均尺寸为6.94μm且90%左右的颗粒尺寸低于10μm),有效降低了复合材料在大尺寸增强颗粒处提前断裂的概率;(2)SiCp的平均长径比为2.43,有效均衡了复合材料的拉伸强度和延伸率;(3)预氧化SiCp导致在SiCp/Al界面处形成MgAl2O4相,为复合材料提供了良好的界面结合强度;(4)PTF技术的运用,极大地提升了SiCp在基体中的分布均匀性,降低了因颗粒团簇而引起的应力集中。上述四种因素为随后的固溶处理奠定基础,经过560℃固溶6h后,复合材料中(5)基体延展性增加且(6)SiCp/Al界面结合强度提升,最终导致复合材料延伸率的显著改善。4.在175℃时效处理的过程中,溶质原子固溶度和位错密度此消彼长的综合作用,导致在整个时效阶段复合材料中析出相的平均尺寸大于基体合金初生α-Al相;而在峰时效和过时效阶段,由于位错协助基体中应变的释放和界面反应消耗掉一定量的Mg元素,复合材料中沉淀相的体积分数降低;其硬度、抗拉强度和屈服强度都呈先升后降的关系,并在时效10h后达到峰值,分别为119.5HV、309MPa和240MPa,较固溶态提高83.0%、12.0%和12.1%,而延伸率持续降低;位错加速沉淀相析出导致复合材料时效进程快于基体合金,而沉淀相较大的平均尺寸和较低的体积分数使复合材料在相同的条件下表现出较低的时效硬化率。5.在时效过程中,固溶强化对复合材料屈服强度的贡献值持续减小,沉淀强化的贡献值先增加后降低,并在峰时效阶段达到最大,而细晶强化、热错配强化和几何必须位错强化对屈服强度的贡献值基本保持不变。总体而言,前两种强化机制对复合材料屈服强度的贡献值较大,而后三种强化机制的贡献值较低且三者贡献度相当。本文中所提出的充分考虑了多种强化机制并引入SiCp失效分数修正后的剪切滞后模型,能够较为精确地预测颗粒增强铝基复合材料在时效过程中的屈服强度。
Abstract
ben wen cai yong yi chong quan xin de ke li zeng jiang lv ji fu ge cai liao zhi bei ji shu —fen mo chu bian cheng xing ji shu (PTF),zhi bei le SiCke li (SiCp)zeng jiang 6061lv (PTF-SiCp/6061Al)ji fu ge cai liao 。shou xian yan jiu le PTF-SiCp/6061Alji fu ge cai liao zai zhi bei tai xia de zu zhi he li xue xing neng jian de guan ji ,tong guo yu PTFji shu zhi bei 6061(PTF-6061)ge jin he jin shu xing zhu zao (PMC)ji shu zhi bei 6061(PMC-6061)ge jin dui bi ,cheng qing le PTFde gong yi te dian he fu ge cai liao de xing neng you shi 。jie zhao ,yan jiu le re chu li dui gai fu ge cai liao zu zhi he li xue xing neng de ying xiang ,fa xian gu rong chu li ke yi tong shi di gao fu ge cai liao de la shen jiang du he yan shen lv ,ren gong shi xiao chu li ke yi shi fu ge cai liao chan sheng ming xian de shi xiao ying hua 。tong guo jian mo ji suan ,jie lou le fu ge cai liao zai gu rong chu li guo cheng zhong de jiang hua 、ren hua ji li ,yi ji shi xiao jiang hua ji li 。yan jiu jie guo biao ming :1.xiang bi yu chuan tong de PMCji shu ,PTFgong yi neng gou ji da de di gao cai liao de zhi mi du 、xi hua jing li he gong jing zu zhi 。PTFfu ge cai liao zhi bei tai de xian wei zu zhi shi you SiCp、jin qiu zhuang de chu sheng α-Alxiang (ping jun che cun wei 16.51μm)he jing jian er ci ning gu zu zhi zu cheng ;er PMCge jin zu zhi ze you cu da de deng zhou jing (90.01μm)he jing jian wang zhuang de gong jing zu zhi gou cheng 。you yu SiCpdui α-Alxiang de jiang hua zuo yong ,fu ge cai liao de kang la jiang du he qu fu jiang du fen bie wei 230MPahe 128MPa,xian zhe gao yu PTF-6061ge jin he PMC-6061ge jin 。2.zai 560℃jing guo 6hgu rong chu li hou ,fu ge cai liao zhong de gong jing zu zhi ji ben rong jie ;you yu SiC/Aljie mian zu ai re chuan di yi ji SiCpdui jing jie de ding za zuo yong ,fu ge cai liao de zu zhi cu hua su lv jiao man ,ji zheng ti gu rong jin cheng yao man yu PTF-6061ge jin ;ji kang la jiang du 、qu fu jiang du he yan shen lv da dao feng zhi ,fen bie wei 276 MPa、214 MPahe 7%,jiao zhi bei tai fen bie di sheng le 20.0%、67.2%he 169.2%。3.zai gu rong chu li guo cheng zhong ,gu rong jiang hua dui fu ge cai liao qu fu jiang du de gong suo zhi zui da ,xi jing jiang hua 、re cuo pei jiang hua he ji he bi xu wei cuo jiang hua dui fu ge cai liao qu fu jiang du de gong suo zhi zhong deng ju xiang dang ,Orowanjiang hua dui fu ge cai liao qu fu jiang du de gong suo zhi shen wei ,zhu yao shi SiCpwei mi ji de che du he ji jiao da de ke li jian ju suo zhi ;tong guo jie ge ge jiang hua ji li he SiCpde shi xiao qing kuang er jian li de xiu zheng jian qie zhi hou mo xing ,jiao hao de yu ce le gai fu ge cai liao zai gu rong guo cheng zhong de qu fu jiang du ;fu ge cai liao zai gu rong guo cheng zhong de ren hua ji li wei :(1)SiCpde che cun jiao xiao (ping jun che cun wei 6.94μmju 90%zuo you de ke li che cun di yu 10μm),you xiao jiang di le fu ge cai liao zai da che cun zeng jiang ke li chu di qian duan lie de gai lv ;(2)SiCpde ping jun chang jing bi wei 2.43,you xiao jun heng le fu ge cai liao de la shen jiang du he yan shen lv ;(3)yu yang hua SiCpdao zhi zai SiCp/Aljie mian chu xing cheng MgAl2O4xiang ,wei fu ge cai liao di gong le liang hao de jie mian jie ge jiang du ;(4)PTFji shu de yun yong ,ji da de di sheng le SiCpzai ji ti zhong de fen bu jun yun xing ,jiang di le yin ke li tuan cu er yin qi de ying li ji zhong 。shang shu si chong yin su wei sui hou de gu rong chu li dian ding ji chu ,jing guo 560℃gu rong 6hhou ,fu ge cai liao zhong (5)ji ti yan zhan xing zeng jia ju (6)SiCp/Aljie mian jie ge jiang du di sheng ,zui zhong dao zhi fu ge cai liao yan shen lv de xian zhe gai shan 。4.zai 175℃shi xiao chu li de guo cheng zhong ,rong zhi yuan zi gu rong du he wei cuo mi du ci xiao bi chang de zeng ge zuo yong ,dao zhi zai zheng ge shi xiao jie duan fu ge cai liao zhong xi chu xiang de ping jun che cun da yu ji ti ge jin chu sheng α-Alxiang ;er zai feng shi xiao he guo shi xiao jie duan ,you yu wei cuo xie zhu ji ti zhong ying bian de shi fang he jie mian fan ying xiao hao diao yi ding liang de Mgyuan su ,fu ge cai liao zhong chen dian xiang de ti ji fen shu jiang di ;ji ying du 、kang la jiang du he qu fu jiang du dou cheng xian sheng hou jiang de guan ji ,bing zai shi xiao 10hhou da dao feng zhi ,fen bie wei 119.5HV、309MPahe 240MPa,jiao gu rong tai di gao 83.0%、12.0%he 12.1%,er yan shen lv chi xu jiang di ;wei cuo jia su chen dian xiang xi chu dao zhi fu ge cai liao shi xiao jin cheng kuai yu ji ti ge jin ,er chen dian xiang jiao da de ping jun che cun he jiao di de ti ji fen shu shi fu ge cai liao zai xiang tong de tiao jian xia biao xian chu jiao di de shi xiao ying hua lv 。5.zai shi xiao guo cheng zhong ,gu rong jiang hua dui fu ge cai liao qu fu jiang du de gong suo zhi chi xu jian xiao ,chen dian jiang hua de gong suo zhi xian zeng jia hou jiang di ,bing zai feng shi xiao jie duan da dao zui da ,er xi jing jiang hua 、re cuo pei jiang hua he ji he bi xu wei cuo jiang hua dui qu fu jiang du de gong suo zhi ji ben bao chi bu bian 。zong ti er yan ,qian liang chong jiang hua ji zhi dui fu ge cai liao qu fu jiang du de gong suo zhi jiao da ,er hou san chong jiang hua ji zhi de gong suo zhi jiao di ju san zhe gong suo du xiang dang 。ben wen zhong suo di chu de chong fen kao lv le duo chong jiang hua ji zhi bing yin ru SiCpshi xiao fen shu xiu zheng hou de jian qie zhi hou mo xing ,neng gou jiao wei jing que de yu ce ke li zeng jiang lv ji fu ge cai liao zai shi xiao guo cheng zhong de qu fu jiang du 。
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论文作者分别是来自兰州理工大学的张学拯,发表于刊物兰州理工大学2019-07-18论文,是一篇关于粉末触变成形论文,颗粒增强铝基复合材料论文,热处理论文,强化机理论文,韧化机理论文,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:粉末触变成形论文; 颗粒增强铝基复合材料论文; 热处理论文; 强化机理论文; 韧化机理论文; 兰州理工大学2019-07-18论文;