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參 考 文 獻(xiàn)1 , et al. Gelcasting a new ceramic forming process. Ceramic bulletin, 1991, 70(10): 1641~16492 Mark A. Janney, Ogbemi O. Omatete, Method for molding ceramics powders using a waterbased gelcasting process, US patent, , Sept. 8, 1992 3 楊金龍, 謝志鵬, 湯強(qiáng)等. αAl2O3懸浮體流變性及凝膠注模成型工藝研究. 硅酸鹽學(xué)報(bào), 1998, 26(1): 41~464 司文捷. 直接凝固注模成型Si3N4及SiC陶瓷-基本原理及工藝過程. 硅酸鹽學(xué)報(bào), 1996, 24(1): 32~375 Huang Y, Ma LG, Tang Q. Surface oxidation to improve waterbased gelcasting of silicon nitride. Journal Of Materials Science 2000, 35(14): 3519~35246 . Yang, . Xie, . Ma, et al. Study on Gelcasting Processing of High Power Rutile Capacitor. Key Engineering Materials, 1999, 161~163 7 Zhou, Longjie, Huang, Yong, Xie, Zhipeng. Gelcasting of concentrated aqueous silicon carbide suspension. Journal of the European Ceramic Society,2000, 20(1): 85~908 陳宗淇, 戴閩光. 膠體化學(xué) 北京:高等教育出版社 1984. 50~689 [英],吳大誠,古大治譯《流變學(xué)導(dǎo)引》 北京:中國石化出版社,1992,20~2910 柏平舟,,1991,4:58~59Study on Gelcasting and Property of Recrystallized Silicon CarbideYi ZhongZhou 1,2, Xie ZhiPeng1, Huang Yong1, Ma JingTao1(1 Department of Materials Science and Engineering, Tsinghua University, Beijing,100084;2 Department of Chemistry, Mengzi Teacher39。(3)以汽化凝結(jié)機(jī)理為燒結(jié)模型,坯體在2450℃和氬氣氛保護(hù)下燒結(jié)可獲得重結(jié)晶碳化硅高溫材料。(2)研究表明, wt.%.%的SiC濃懸浮體。4 結(jié) 論(1)通過沉降實(shí)驗(yàn)及Zeta電位和粘度值的測定,發(fā)現(xiàn)分散劑、pH值、固相體積分?jǐn)?shù)對SiC濃懸浮體的本征流變特性影響很大。一般地,固相體積分?jǐn)?shù)越高,則坯體致密度越大,燒結(jié)體強(qiáng)度越高。由圖6(b)可看出SiC顆粒明顯長大,氣孔分布均勻,并伴隨著細(xì)顆粒被兼并形成大顆粒之間的橋連結(jié)構(gòu)及氣孔率較小的燒結(jié)體。這種汽化凝結(jié)機(jī)理作用的結(jié)果,使得在顆粒的接觸處形成新的晶界,發(fā)生顆粒的共生現(xiàn)象,從而形成堅(jiān)實(shí)的燒結(jié)體。在接融點(diǎn)范圍內(nèi)主要是凹形彎曲,當(dāng)兩個(gè)微粒相接觸時(shí),其凹度尤為明顯,以致此處的蒸汽特別低。 汽化凝結(jié)機(jī)理