本文主要研究内容
作者杨春萍（2019）在《高强韧Si3N4导热陶瓷制备及其组织性能调控》一文中研究指出：Si3N4陶瓷具有高强度、高韧性及高硬度等特性,是综合性能最优异的结构陶瓷之一。不仅如此,其室温理论热导率高达200320W·m-1K-1,有望替代强度低、易潮解的AlN陶瓷,成为新一代高性能陶瓷基板材料,在超大规模集成电路散热系统领域具有广泛的应用前景。然而,目前获得的Si3N4陶瓷的热导率与理论值差距较大,应用传统的烧结技术和烧结助剂体系很难协同优化材料的导热/力学综合性能。如通过延长烧结时间可获得热导率超过100W·m-1K-1的Si3N4陶瓷,失去了高强度的特性。因此,短时、高效制备高强、高导热Si3N4陶瓷具有重要的研究意义。本文以商业化α-Si3N4为主要原料,采用气压烧结、SPS烧结结合高温热处理工艺制备了Si3N4陶瓷,研究了烧结助剂组分、制备工艺参数对材料致密化、相转变、显微结构及性能的影响规律,通过调节材料组分及优化工艺参数实现了高强度、高导热Si3N4陶瓷的制备。探讨了显微结构对导热性能的影响机制。研究发现,利用Y2O3、Yb2O3和Gd2O3与MgSiN2为复合烧结助剂,采用气压烧结工艺制备Si3N4陶瓷时,稀土离子半径增大,Si3N4陶瓷的致密度降低,晶粒平均尺寸减小,大晶粒相对含量降低,热导率降低。采用两步法气压烧结工艺制备Si3N4陶瓷,能够有效促进离子扩散和封闭气孔的排除,将Si3N4陶瓷的致密度提高到99.4%,平均晶粒尺寸提高到7.3μm,尺寸大于5μm的晶粒相对含量高达68.13%,热导率达到60W·m-1K-1,相比一步法气压烧结提高了3.4%。使用低熔点无氧化合物MgF2替代MgO和MgSiN2,结合Y2O3为复合烧结助剂,应用SPS烧结技术与后续热处理制备Si3N4陶瓷,有效降低了液相形成温度和液相粘度,提高了N元素在液相中的溶解度,促进了材料的致密化,提高了相转变速率,促进晶粒生长。F元素与Si元素形成挥发相SiF4,能够有效降低晶界相含量,有助于提高热导率。经高温热处理后,烧结助剂组分为3mol%Y2O3-2mol%MgF2时,材料热导率达到76W·m-1K-1。在α-Si3N4原料粉中引入β-Si3N4晶种实现了对Si3N4陶瓷显微结构的调控,优化了材料的导热及力学性能。提高β-Si3N4晶种添加量,大尺寸晶粒相对含量先升高后降低。当晶种含量为10mol%时,Si3N4陶瓷的大尺寸β-Si3N4棒晶相对含量达到最大值,同时,试样获得最优的综合性能,室温热导率为84.6W·m-1K-1,测试温度为500℃时热导率为26.8W·m-1K-1,抗弯强度为893MPa,断裂韧性为7.8MPa·m1/2,维氏硬度为16.8GPa。在SPS烧结工艺条件下,选用低熔点的MgF2为烧结助剂,降低液相粘度,促进离子扩散,使垂直于SPS烧结压力方向的晶粒生长更为迅速,加剧了热导率在不同压力方向的差异。提高β-Si3N4晶种含量,大幅提高了烧结过程中的形核量,降低了晶粒生长空间受限,长棒晶在烧结压力的作用下进行偏转的移动范围减小,削弱了材料组织和性能的各向异性。添加晶种的Si3N4晶粒内部具有核壳结构,核壳具有相同的结构和晶体取向,外延生长始于β-Si3N4晶种。使用Y2O3-MgF2为烧结助剂的Si3N4陶瓷平衡非晶膜厚度为1.05nm。为降低晶界能,在界面处存在台阶。β-Si3N4晶粒内部O元素含量低于0.7%,在β晶粒内部及晶界相中F元素含量均低于0.1%。大部分F元素与Si元素形成挥发相SiF4,降低了晶界相含量。降低晶格内的O含量及晶界相含量均能有效提高Si3N4陶瓷的热导率。采用SPS烧结及后续热处理工艺,使用氟化物烧结助剂制备的高导热Si3N4陶瓷,通过添加晶种调控显微结构来协同优化其导热及力学性能,在高性能陶瓷基板领域具有广泛的应用前景。
Abstract
Si3N4tao ci ju you gao jiang du 、gao ren xing ji gao ying du deng te xing ,shi zeng ge xing neng zui you yi de jie gou tao ci zhi yi 。bu jin ru ci ,ji shi wen li lun re dao lv gao da 200320W·m-1K-1,you wang ti dai jiang du di 、yi chao jie de AlNtao ci ,cheng wei xin yi dai gao xing neng tao ci ji ban cai liao ,zai chao da gui mo ji cheng dian lu san re ji tong ling yu ju you an fan de ying yong qian jing 。ran er ,mu qian huo de de Si3N4tao ci de re dao lv yu li lun zhi cha ju jiao da ,ying yong chuan tong de shao jie ji shu he shao jie zhu ji ti ji hen nan xie tong you hua cai liao de dao re /li xue zeng ge xing neng 。ru tong guo yan chang shao jie shi jian ke huo de re dao lv chao guo 100W·m-1K-1de Si3N4tao ci ,shi qu le gao jiang du de te xing 。yin ci ,duan shi 、gao xiao zhi bei gao jiang 、gao dao re Si3N4tao ci ju you chong yao de yan jiu yi yi 。ben wen yi shang ye hua α-Si3N4wei zhu yao yuan liao ,cai yong qi ya shao jie 、SPSshao jie jie ge gao wen re chu li gong yi zhi bei le Si3N4tao ci ,yan jiu le shao jie zhu ji zu fen 、zhi bei gong yi can shu dui cai liao zhi mi hua 、xiang zhuai bian 、xian wei jie gou ji xing neng de ying xiang gui lv ,tong guo diao jie cai liao zu fen ji you hua gong yi can shu shi xian le gao jiang du 、gao dao re Si3N4tao ci de zhi bei 。tan tao le xian wei jie gou dui dao re xing neng de ying xiang ji zhi 。yan jiu fa xian ,li yong Y2O3、Yb2O3he Gd2O3yu MgSiN2wei fu ge shao jie zhu ji ,cai yong qi ya shao jie gong yi zhi bei Si3N4tao ci shi ,xi tu li zi ban jing zeng da ,Si3N4tao ci de zhi mi du jiang di ,jing li ping jun che cun jian xiao ,da jing li xiang dui han liang jiang di ,re dao lv jiang di 。cai yong liang bu fa qi ya shao jie gong yi zhi bei Si3N4tao ci ,neng gou you xiao cu jin li zi kuo san he feng bi qi kong de pai chu ,jiang Si3N4tao ci de zhi mi du di gao dao 99.4%,ping jun jing li che cun di gao dao 7.3μm,che cun da yu 5μmde jing li xiang dui han liang gao da 68.13%,re dao lv da dao 60W·m-1K-1,xiang bi yi bu fa qi ya shao jie di gao le 3.4%。shi yong di rong dian mo yang hua ge wu MgF2ti dai MgOhe MgSiN2,jie ge Y2O3wei fu ge shao jie zhu ji ,ying yong SPSshao jie ji shu yu hou xu re chu li zhi bei Si3N4tao ci ,you xiao jiang di le ye xiang xing cheng wen du he ye xiang nian du ,di gao le Nyuan su zai ye xiang zhong de rong jie du ,cu jin le cai liao de zhi mi hua ,di gao le xiang zhuai bian su lv ,cu jin jing li sheng chang 。Fyuan su yu Siyuan su xing cheng hui fa xiang SiF4,neng gou you xiao jiang di jing jie xiang han liang ,you zhu yu di gao re dao lv 。jing gao wen re chu li hou ,shao jie zhu ji zu fen wei 3mol%Y2O3-2mol%MgF2shi ,cai liao re dao lv da dao 76W·m-1K-1。zai α-Si3N4yuan liao fen zhong yin ru β-Si3N4jing chong shi xian le dui Si3N4tao ci xian wei jie gou de diao kong ,you hua le cai liao de dao re ji li xue xing neng 。di gao β-Si3N4jing chong tian jia liang ,da che cun jing li xiang dui han liang xian sheng gao hou jiang di 。dang jing chong han liang wei 10mol%shi ,Si3N4tao ci de da che cun β-Si3N4bang jing xiang dui han liang da dao zui da zhi ,tong shi ,shi yang huo de zui you de zeng ge xing neng ,shi wen re dao lv wei 84.6W·m-1K-1,ce shi wen du wei 500℃shi re dao lv wei 26.8W·m-1K-1,kang wan jiang du wei 893MPa,duan lie ren xing wei 7.8MPa·m1/2,wei shi ying du wei 16.8GPa。zai SPSshao jie gong yi tiao jian xia ,shua yong di rong dian de MgF2wei shao jie zhu ji ,jiang di ye xiang nian du ,cu jin li zi kuo san ,shi chui zhi yu SPSshao jie ya li fang xiang de jing li sheng chang geng wei xun su ,jia ju le re dao lv zai bu tong ya li fang xiang de cha yi 。di gao β-Si3N4jing chong han liang ,da fu di gao le shao jie guo cheng zhong de xing he liang ,jiang di le jing li sheng chang kong jian shou xian ,chang bang jing zai shao jie ya li de zuo yong xia jin hang pian zhuai de yi dong fan wei jian xiao ,xiao ruo le cai liao zu zhi he xing neng de ge xiang yi xing 。tian jia jing chong de Si3N4jing li nei bu ju you he ke jie gou ,he ke ju you xiang tong de jie gou he jing ti qu xiang ,wai yan sheng chang shi yu β-Si3N4jing chong 。shi yong Y2O3-MgF2wei shao jie zhu ji de Si3N4tao ci ping heng fei jing mo hou du wei 1.05nm。wei jiang di jing jie neng ,zai jie mian chu cun zai tai jie 。β-Si3N4jing li nei bu Oyuan su han liang di yu 0.7%,zai βjing li nei bu ji jing jie xiang zhong Fyuan su han liang jun di yu 0.1%。da bu fen Fyuan su yu Siyuan su xing cheng hui fa xiang SiF4,jiang di le jing jie xiang han liang 。jiang di jing ge nei de Ohan liang ji jing jie xiang han liang jun neng you xiao di gao Si3N4tao ci de re dao lv 。cai yong SPSshao jie ji hou xu re chu li gong yi ,shi yong fu hua wu shao jie zhu ji zhi bei de gao dao re Si3N4tao ci ,tong guo tian jia jing chong diao kong xian wei jie gou lai xie tong you hua ji dao re ji li xue xing neng ,zai gao xing neng tao ci ji ban ling yu ju you an fan de ying yong qian jing 。
论文参考文献
论文详细介绍
论文作者分别是来自哈尔滨工业大学的杨春萍，发表于刊物哈尔滨工业大学2019-12-07论文，是一篇关于陶瓷论文,热导率论文,烧结论文,氟化物论文,晶种论文,哈尔滨工业大学2019-12-07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，资料来自哈尔滨工业大学2019-12-07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。