碳包纳米氧化锆粉体的烧结行为与力学性能

采用粉体表面包碳技术和两步烧结方法制备出具有良好力学性能的细晶3Y-TZP材料,研究了在无压烧结和两步烧结条件下,碳含量对碳包3Y-TZP材料烧结行为及力学性能的影响.结果表明:对于包裹少量碳的3Y-TZP,与未包碳的试样相比,采用两步烧结不但能提高材料的密度还能细化晶粒;结构致密和ZrO2相变增韧使材料具有较高的维氏硬度和断裂韧性.在碳含量为1.5%时,3Y-TZP材料的维氏硬度和断裂韧性达最大值,碳含量进一步提高使材料中的气孔和缺陷增多,导致材料的性能下降.

Sintering behaviors and mechanical properties of carbon-coated ZrO2 nano-powders

Tetragonal zirconia polycrystals (TZP) stabilized with 3% (molar fraction) Y_2O_3 (3Y- TZP) with superfine grains and high mechanical properties were obtained at two-stage sintering by using ZrO_2 nano-powders coated with carbon.Effects of carbon content on sintering behaviors and mechanical properties of carbon-coated 3Y-TZP sintered at normally continuous sintering and two-stage sintering were investigated.Results show that,3Y-TZP with a little of carbon sintered at two-stage sintering can give denser microstructure and finer grain size compared to carbon-uncoated 3Y-TZP.Vickers hardness and fracture toughness of the materials increase to the maximum values at 1.5% carbon content because of denser microstructure and phase transformation toughening and then decrease due to more pore after oxidation of carbon.