PDF/月刊誌論文/code:pg_0201_09 マテリアル インテグレーション 2002年1月号
INTER MATERIAL 21世紀に飛躍する材料(3)新材料とその応用
解説
Processing of Homogeneous Nanocomposites
■著者
Centre for Advanced Materials Technology、 School of Aerospace、 Mechanical and Mechatronic Engineering、University of Sydney　A.J.Ruys

■要約
Homogeneous zirconia-toughened alumina(ZTA)nanocomposites were fabricated by ananoparticle-microparticle homogenisation pro-cess.Zirconia nanoparticles were precipitatedfrom zirconyl chloride solutions via a ureathermohydrolysis process. A high urea concen-tration,[CO(NH2 )2 =5[ZrOCl2 ,resulted in theprecipitation of a gel regardless of ZrOCl2concen-tration.A low urea concentration,[CO(NH2 )2 =0.5[ZrOCl2 ,resulted in the precipitation ofunagglomerated ZrO2nanoparticles as small as0 nm and as large as 100nm.The parti-cle size was dependent on the zirconyl chlorideconcentration and increased at an exponentiallydecreasing rate with respect to [ZrOCl2 ,bya relationship approximately de ned as D =288 [ZrOCl2 0.7. These nanoparticle suspensions were mixed with alumina powder (500nm aluminaparticle size),homogenised,and the suspensionsdewatered and consolidated into nanocompos-ite specimens. Electron microscopy of sinteredspecimens demonstrated excellent homogeneityof nanoparticle distribution.Fracture toughnesswas found to correlate linearly with nanoparticleconcentration for these specimens within the rangetested,0 to 10 volume% zirconia nanoparticles,increasing linearly from about 3 MPa.m1/2 toabout 5 MPa.m1/2 across this range.