更新时间:06-10 上传会员:sana0722
分类:理工论文 论文字数:10659 需要金币:1000个
摘要:ZTA 复合陶瓷的增韧机理是基体晶粒的细化、相变韧化、微裂纹增韧、裂纹的转向与分叉,ZrO2存在的从四方到单斜的相变被认为是改善陶瓷脆性的有效途径。由于氧化锆基氧化铝复合陶瓷基板存在流变性弱、脆性较强,陶瓷容易破碎,本文在此基础上做相应改变,即将氧化铝作为基板用氧化锆来增韧,制出硬度强、韧性好、抗腐蚀性强、抗热震性好的复合陶瓷基板。
本文研究了氧化铝和氧化锆两种材料进行复合的最佳粉料比,充分利用各相的优点以弥补其不足,分析并确定了最佳固相体积分数,即在保证成型所需流动性的前提下,凝胶注模技术还要求浆料应具有尽可能高的固相含量,实验通过对不同体积分数(固相含量从40%-55%)进行对比实验研究的到了最佳固相体积分数。采用凝胶注模成型技术制备Al2O3/ZrO2有色复合陶瓷,测定不同体积分数的氧化铝/氧化锆悬浮体的粘度,得到粘度与剪切速率曲线;测定悬浮体的pH值并讨论其对坯体的影响。在制备悬浮体的同时加入硝酸钴作为增色剂,目的是使制出的陶瓷美观。针对表面氧阻聚,本文通过采用表面改性的方法,既不增加坯体内有机物的含量,也不降低坯体的强度,使坯体表面不起皮、不剥落,从而制得密度大、均匀性好、抗弯强度大、抗腐蚀性强的Al2O3/ZrO2有复色合陶瓷。对干燥脱模过程做了详尽陈述,同时研究了坯体的烧结温度曲线。
结果表明,通过坯体性能参数的比较知道氧化铝氧化锆两种材料复合的最佳粉料比为80:20;最佳固相体积分数确定为45%;最适pH值为7.8,此时悬浮体的流变性最好,最适合注模成型,制作出的配体成型好,不收缩;加入w5%的聚乙烯吡咯烷酮(PVP)能有效克服氧阻聚;加入w1%的硝酸钴就可以达到很好的增色效果;烧结温度控制在15000C,经物相分析测试知,制得的有色复合陶瓷的体积密度、抗弯强度、硬度、韧性、抗腐蚀性、抗热震性均高于单一氧化锆陶瓷和氧化铝陶瓷。
关键词:凝胶注模成型;粉料比;聚乙烯吡咯烷酮 (PVP);烧结温度;有色复合陶瓷
ABSTRACT:The composite ceramic ZTA as well as steatite introduced. toughening mechanism is matrix grain refinement and transformation of micro cracks and toughening the toughening, crack steering and bifurcate, existing ZrO2 from the four to single inclined phase change is considered the effective ways to improve ceramic brittle. Because zirconia base aluminum oxide compound ceramic substrates exists weak, brittle strong rheology, ceramic easily broken, in this article, based on the corresponding change upcoming alumina with zirconia as substrate to toughening, Strong hardness transplantable and good toughness, corrosion resistance is strong, thermal shock resistance good composite ceramic substrates.
This paper studies the alumina and zirconia two materials the best powder composite than, make full use of the advantages of each phase to cover their inadequacy, analysis and determined the best solid-phase volume fraction, namely needed liquidity in guarantee under the premise of shape, gel injection molding technology also requires slurry should have as high solid content, experiment through different volume fraction (solid content from 40 - 55 percent) compared to the best of the experimental study of solid-phase volume fraction. Adopt gel mould molding technology preparation Al2O3/ZrO2 non-ferrous composite ceramic, measuring different volume fraction of Al2O3/ZrO2 suspension body the viscosity, get viscosity and shear rate curves; Determination of suspension body pH value and discuss the influence of the billet body .In the preparation of suspension body simultaneously to join nitric acid cobalt as graces agent, the purpose is to make produce ceramic beautiful. According to surface oxygen inhibitor, In this paper, the method of using surface modification. Neither increase in the content of organic matter, strand don't reduce the intensity, given photo-cell and make billet body surface not peeling, don't flake, thus made big density, good uniformity, flexural strength and corrosion resistance strong Al2O3/ZrO2 have multi-color and ceramics. Demoulding process of dry made detailed statement, given photo-cell and also studied the sintering temperature curve.
The results show that: Through comparison of given photo-cell and performance parameters of alumina zirconia two that composite than the best powder for 80:20; Best solid-phase volume fraction determined for 45 percent; The optimal pH value for 7.8,At best, the rheology of suspension body. The most suitable for injection molding forming, produce ligand forming good, No shrinkage; Join w5 % polyethylene pyrrole (PVP) can effectively overcome oxygen inhibitor; Join w1 % of nitric acid cobalt can achieve good graces effect;The sintering temperature control in 15000C, the analysis test object is known system of non-ferrous composite ceramic volume density, flexural strength, hardness and toughness, corrosion resistance, thermal shock resistance are higher than the single zirconia ceramics and alumina ceramics.
Keywords: Gel mould molding; Powder ratio; Polyethylene pyrrole (PVP); The sintering temperature; Non-ferrous composite ceramic