JOSE OCTAVIO ARMANI PASCHOAL
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Artigo IPEN-doc 29513 Room temperature plasticity of zirconia-yttria-titania ceramics2022 - USSUI, VALTER; LAZAR, DOLORES R.R.; LIMA, NELSON B. de; ARATA, ANELYSE; RIBEIRO, FABIO N.; DALPIAN, GUSTAVO M.; MARCHI, JULIANA; PASCHOAL, JOSE O.A.Yttria-stabilized tetragonal zirconia (Y-TZP) ceramics have excellent mechanical properties. However, such materials cannot undergo plastic deformation at room temperature due to their high hardness and brittleness values, hindering machinability. To overcome these limitations, we propose a zirconia-yttria-titania ceramics, based on zirconia containing 3mol% yttria and up to 15mol% titania. The zirconia-yttria-titania powders were synthesized by co-precipitation method, uniaxially pressed and sintered at 1400°C/5 h. Sample characterizations were carried out by X-ray diffraction, scanning electron microscopy and mechanical properties through Vickers hardness and toughness measurements. Compared to the Y-TZP ceramics, the yttria stabilised tetragonal zirconia ceramics co-doped with 10mol%Ti showed noticeable increase of tetragonality parameter, higher toughness and lower hardness values, indicating plasticity at room temperature. Furthermore, the atomistic simulation by Density Functional Theory methodology suggests the occurrence of spatial arrangement of the atoms, explaining the proposed plasticity.Artigo IPEN-doc 09088 The influence of sulphur on the processing of zirconia based ceramics2002 - LAZAR, D.R.R.; MENEZES, C.A.B.; USSUI, V.; BRESSIANI, A.H.A.; PASCHOAL, J.O.A.Artigo IPEN-doc 09682 Synthesis of ZrOsub(2) - based ceramics for applications in SOFC2003 - USSUI, V.; LEITAO, F.; YAMAGATA, C.; MENEZES, C.A.B.; LAZAR, D.R.R.; PASCHOAL, J.O.A.Artigo IPEN-doc 09685 The role of light rare earth on thermal degradation behaviour of ZrOsub(2)-CeOsub(2)-Ysub(2)Osub(3) ceramics2003 - MENEZES, C.A.B.; LAZAR, D.R.R.; USSUI, V.; LIMA, N.B.; PASCHOAL, J.O.A.Artigo IPEN-doc 09687 Evaluation of hardness and fracture toughness of TZP ceramics stabilized with yttria concentrates2003 - LAZAR, D.R.R.; MENEZES, C.A.B.; USSUI, V.; FANCIO, E.; LIMA, N.B.; BRESSIANI, A.H.A.; PASCHOAL, J.O.A.Artigo IPEN-doc 11220 Evaluation of the effect of heavy rare earth elements on electrical resistivity of zirconia-yttria ceramics2005 - LAZAR, D.R.R.; USSUI, V.; MUCCILLO, E.N.S.; BRESSIANI, A.H.A.; PASCHOAL, J.O.A.Artigo IPEN-doc 11226 Synthesis and characterization of NiO-8YSZ powders by coprecipitation route2005 - YOSHITO, W.K.; USSUI, V.; LAZAR, D.R.R.; PASCHOAL, J.O.A.