复合添加MgO和La_(2)O_(3)对纳米微晶氧化铝陶瓷微观结构的影响  

Effects of MgO and La_(2)O_(3) Composite Additives on Microstructure of Nano-Microcrystalline Alumina Ceramics

作　　者：李慧[1] 张金平[1] 高景霞[1] 王二萍[1] 张洋洋[1] LI Hui;ZHANG Jinping;GAO Jingxia;WANG Erping;ZHANG Yangyang(Engineering Department,Huanghe Science and Technology College,Zhengzhou 450006,China)

机构地区：[1]黄河科技学院工学部,郑州450006

出　　处：《硅酸盐通报》2024年第1期339-346,共8页Bulletin of the Chinese Ceramic Society

基　　金：河南省科技攻关项目(212102210187,212102210603,232102210183)。

摘　　要：纳米微晶氧化铝磨料具有良好的通用性和高精度磨削能力,且性价比较高,在机械制造、轴承、模具、汽车等领域有广泛的应用潜力。本研究以勃姆石(γ-AlOOH)为原料,MgO、La_(2)O_(3)为添加剂,采用溶胶-凝胶工艺合成纳米微晶氧化铝。通过差示扫描量热仪、X射线衍射仪、扫描电子显微镜和从头算分子动力学方法模拟计算研究了添加剂对微晶氧化铝相转化、物相组成、微观结构及力学性能的影响。结果表明:复合添加MgO和La2O3可以使氧化铝中间相θ-Al_(2)O_(3)向α-Al_(2)O_(3)转化的温度从1257℃降低到1105℃,将致密化温度从1600℃降低到1350℃,将微晶氧化铝的晶粒尺寸从1.04 mm减小到120 nm,实现了低温致密烧结。The nanocrystalline alumina abrasive,with its excellent versatility and high-precision grinding capability,has become a cost-effective choice for various applications in fields such as mechanical manufacturing,bearings,molds and automobiles.In this study,nano microcrystalline alumina was synthesized by sol-gel process,with boehmite(γ-AlOOH)as raw material,MgO and La_(2)O_(3) as additives.The effects of MgO and La_(2)O_(3) additives on the phase transformation,phase composition,microstructure and mechanical properties of nanocrystalline alumina were investigated by differential scanning calorimetry,X-ray diffraction,scanning electron microscopy and ab initio molecular dynamics simulation.The results show that MgO and La_(2)O_(3) composite additives can reduce the transformation temperature of alumina from the intermediate phaseθ-Al_(2)O_(3) toα-Al_(2)O_(3) from 1257℃ to 1105℃,lower the densification temperature of the material from 1600℃to 1350℃,and reduce the grain size of nanocrystalline alumina from 1.04 mm to 120 nm,thus realizing the low-temperature dense sintering.

关 键 词：纳米微晶 Al_(2)O_(3) MGO La_(2)O_(3) 溶胶-凝胶 添加剂 低温烧结 

分 类 号：TB321[一般工业技术—材料科学与工程]