Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
Division of Advanced Materials Engineering and the Research Center of Hydrogen Fuel Cell, Engineering College, Chonbuk National University, 561-756, Republic of Korea.
J Nanosci Nanotechnol. 2019 Apr 1;19(4):2417-2420. doi: 10.1166/jnn.2019.15985.
As nanostructured materials possess high strength, high hardness, excellent ductility and toughness, undoubtedly, more attention has been paid for the application of nanomaterials. When conventional sintering processes are used to sinter nano-sized zirconia powders, concomitant grain growth leads to the destruction of the nanostructure. This focuses attention on consolidation methods in which grain growth can be eliminated or significantly reduced. To accomplish this, rapid sintering methods have been widely used to sinter nano-sized powders. Nanopowders of ZrO₂ and 3YSZ were fabricated and rapidly consolidated using high-energy ball milling and the pulsed current activated sintering (PCAS). The sintering behavior and crystallite size ZrO₂ and 3YSZ powders were evaluated. A nanostructured dense 3YSZ compact with a relative density of up to 99% was readily obtained within one min. The hardness and fracture toughness of ZrO₂ and 3YSZ sintered from powders milled for 10 h were 450 and 1160 kg/mm², 3 and 4.4 MPa·m. Not only hardness but also fracture toughness of 3YSZ are higher than those of ZrO₂.
由于纳米结构材料具有高强度、高硬度、优异的延展性和韧性，因此纳米材料的应用无疑引起了更多的关注。当采用传统的烧结工艺来烧结纳米尺寸的氧化锆粉末时，伴随而来的晶粒生长会导致纳米结构的破坏。这就需要关注那些可以消除或显著减少晶粒生长的固结方法。为了实现这一目标，人们广泛采用快速烧结方法来烧结纳米级粉末。采用高能球磨和脉冲电流激活烧结（PCAS）制备了 ZrO₂和 3YSZ 的纳米粉末，并对其进行了快速固结。评估了 ZrO₂和 3YSZ 粉末的烧结行为和晶粒尺寸。在 1 分钟内，很容易获得相对密度高达 99%的纳米结构致密 3YSZ 压坯。经过 10 小时球磨的 ZrO₂和 3YSZ 粉末的烧结硬度和断裂韧性分别为 450 和 1160 kg/mm²、3 和 4.4 MPa·m。3YSZ 的硬度和断裂韧性不仅高于 ZrO₂，而且还具有较高的断裂韧性。
