Oh Sung-Tag, Lee Sung-Il
Department of Materials Science and Engineering, Seoul National University of Technology, Seoul 139-743, Korea.
J Nanosci Nanotechnol. 2010 Jan;10(1):366-9. doi: 10.1166/jnn.2010.1544.
The processing conditions to prepare nano-sized Cu and Mo dispersed Al2O3 (Al2O3/Cu and Al2O3/Mo) composites by pressureless sintering were explored. The composite powders of Al2O3/Cu and Al2O3/Mo were obtained by the hydrogen reduction of Al2O3/CuO and Al2O3/MoO3 powder mixtures and consolidated by pressureless sintering using infrared heating furnace with a heating rate of 200 degrees C/min. SEM and TEM analyses for the composite showed that the nano-sized metal particles were well distributed and situated on the grain boundaries of the Al2O3 matrix. The nanocomposites, sintered at 1300 to 1500 degrees C for 4 min, showed the relative density of above 90%. Maximum hardness of 16.1 GPa was obtained in Al2O3/Cu nanocomposites with sintering additive of 1 wt% MgO. The sintered nanocomposites exhibited the enhanced fracture toughness of above 4.5 MPa x m(1/2), compared with monolithic Al2O3. The mechanical properties were discussed in terms of observed microstructural characteristics.
探索了通过无压烧结制备纳米尺寸的铜和钼分散的氧化铝（Al2O3/Cu和Al2O3/Mo）复合材料的工艺条件。Al2O3/Cu和Al2O3/Mo复合粉末是通过对Al2O3/CuO和Al2O3/MoO3粉末混合物进行氢还原而获得的，并使用加热速率为200℃/min的红外加热炉通过无压烧结进行固结。对复合材料的扫描电子显微镜（SEM）和透射电子显微镜（TEM）分析表明，纳米尺寸的金属颗粒分布良好，位于Al2O3基体的晶界上。在1300至1500℃下烧结4分钟的纳米复合材料显示出相对密度高于90%。在添加1 wt% MgO烧结添加剂的Al2O3/Cu纳米复合材料中获得了16.1 GPa的最大硬度。与块状Al2O3相比，烧结后的纳米复合材料表现出增强的断裂韧性，高于4.5 MPa×m(1/2)。根据观察到的微观结构特征对力学性能进行了讨论。
