研究目的
To produce nanopowder and dense nanostructured ZrO2 and 3YSZ materials using pulsed current activated sintering (PCAS) and compare their microstructure and mechanical properties.
研究成果
Nanopowders of ZrO2 and 3YSZ were successfully fabricated and consolidated using PCAS, achieving high density and retained nanostructure. 3YSZ showed lower sintering temperature, higher density, hardness, and fracture toughness compared to ZrO2, attributed to oxygen vacancies and crystal structure differences. The method is effective for rapid sintering with minimal grain growth.
研究不足
The study may have limitations in scalability for industrial applications, potential for impurity introduction during milling not fully addressed, and the short sintering time might not be optimized for all material types. Temperature gradients in PCAS could affect uniformity, and the method's applicability to other nanomaterials is not explored.
1：Experimental Design and Method Selection:
The study used high-energy ball milling and pulsed current activated sintering (PCAS) to fabricate and consolidate nanopowders of ZrO2 and 3YSZ, aiming to minimize grain growth and achieve high density.
2：Sample Selection and Data Sources:
Commercial ZrO2 powder (
3：7% pure, -325 mesh) from Alfa, Inc. and 3YSZ powder (9% pure, -325 mesh) from Tosoh were used. List of Experimental Equipment and Materials:
High-energy ball mill (Pulverisette-5 planetary mill), tungsten carbide balls (8 mm diameter), stainless steel vial, graphite die (OD 35 mm, ID 10 mm, height 40 mm), pulsed current activated sintering system (Eltek Co., Korea), pyrometer, linear gauge, X-ray diffraction (XRD) equipment, field emission scanning electron microscope (FE-SEM) with energy dispersive spectroscopy (EDS), Vickers hardness tester.
4：Experimental Procedures and Operational Workflow:
Powders were milled at 300 rpm for 10 h under argon atmosphere with a balls-to-powder ratio of 30:
5：Milled powders were placed in a graphite die, evacuated, uniaxial pressure of 80 MPa applied, pulsed current activated under vacuum (240 mtorr), temperature measured by pyrometer, shrinkage measured by linear gauge, sintered for about one min, cooled to room temperature. Relative density measured by Archimedes method, microstructural analysis via XRD and FE-SEM with EDS, hardness and fracture toughness measured using Vickers indentation at 5 kg load and 15 s dwell time. Data Analysis Methods:
Crystallite size calculated from XRD peak broadening using Suryanarayana and Grant Norton's formula, fracture toughness estimated using Niihara's expression from crack lengths.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
