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摘要本文主要通过三个方面对湿法成型及烧结致密化进行研究。一是利用球磨工艺和添加烧结助剂的方法对氧化铝商业粉体的改性。二、寻找合适的分散剂对粉体进行分散以获得流动性和分散性好、粘度小、固含量高的浆料。三、对氧化铝透明陶瓷的烧结行为进行研究，目的是获得湿法成型的大尺寸半透明氧化铝陶瓷。50533
通过研究发现选用PAA-NH4为球磨介质球磨4h后得到的粉体颗粒最小且分布均一，颗粒主体集中在8-10μm左右。氧化镁含量在0.2wt%时陶瓷的透过率最好，适量的氧化镁可以抑制晶粒生长和晶界迁移，能够使气孔有充足的时间靠晶界迁移而慢慢排出，使陶瓷烧结致密化。但是如果加入1wt%的氧化镁，氧化铝的透过率便会降低，可能由于加入过量的氧化镁而产生第二相，影响了陶瓷透过性。在得到可透明的改性粉体后，一方面将改性的粉体通过干法成型进行烧结，研究烧结气氛、烧结温度和保温时间对透过率的影响，发现氢气气氛下以1820℃烧结保温10h能得到透过率为51%的氧化铝陶瓷。另一方面对加入不同分散剂的氧化铝浆料做进行比分析，发现PAA-NH4的分散性最好，且浆料流动性好、固含量高能达到30%，完全满足注浆的条件。最后通过加入0.2wt%的MgO，以PAA-NH4为分散介质，球磨4h后，将浆料经过排气、注浆等工艺获得的素胚进行烧结，得到大尺寸氧化铝半透明陶瓷。
毕业论文关键词： 氧化铝；透明陶瓷；湿法成型；粉体改性；烧结制度；
Abstract
This article mainly studies three aspects for wet molding and sintering densification. The first is by ball milling process and adding magnesium oxide sintering additives on the commercial alumina powder modification, and then look for suitable dispersant of powder dispersed to obtain liquidity and good, low viscosity, high solid content of slurry dispersion and finally to transparent alumina ceramic sintering behavior research, the purpose of which is to obtain large size translucent alumina ceramic.
Through the study found that the use of PAA-NH4 as the ball milling medium after ball milling 4H obtained the smallest and distribution of the powder particles, the particle concentration in the 8-10μm. Magnesium oxide content in 0.2wt% ceramic transmittance best，amount of magnesium oxide can inhibit grain growth and grain boundary migration, can make pores have time on grain boundary migration and slowly discharge, the Sintering Densification of ceramic. However, if Magnesium Oxide joined the 1wt%, the transmission rate of alumina will be reduced, may be due to excessive and resulting in the second phase, affecting the permeability of the ceramic. In the transparent powder after the change, on the one hand will be changed of powder by dry pressing sintering, of sintering atmosphere, sintering temperature and holding time on through rate, found under hydrogen atmosphere in 1820 DEG C sintering insulation 10h can get the permeation rate was 51% alumina ceramics. Another convenient for the addition of different dispersion of alumina slurry to do comparative analysis, found that the PAA-NH4 of the best dispersion, and the slurry fluidity good, solid content of 30%, fully meet the conditions of grouting. Finally, through the addition of MgO 0.2wt%, PAA-NH4 as the dispersion medium, after the ball milling 4h, the slurry through the exhaust, grouting and other processes to obtain the prime embryos for sintering, Get large size alumina translucent ceramic.
Key words: Alumina; Transparent ceramics; Wet forming; Powder modification; Sintering system；
目录
第1章 绪论 1
1.1透明陶瓷材料概述 1
1.2氧化铝透明陶瓷研究进展 2