Development of a Cubic-Anvil Experimental Facility for High Pressure and Current Sintering of Bulk Nanocrystalline Materials

该奖项为购买用于机械测试和热力学研究的具有纳米晶体微观结构的材料的大体积部件的制造设备提供支持。这个新的制造系统的支柱将是立方砧装置。多砧有效载荷由一台1000吨单轴液压机驱动，该液压机配备了自动化压力和温度控制，用于定制加工。该设备的独特之处在于将超高压（高达5 Gpa）和大样品容量（5-10 cc）的有效载荷与电阻和脉冲直流电加热相结合，适用于当前的等离子体活化烧结系统。利用该装置回收的大型纳米晶样品为研究烧结行为、确定机械性能以及表征各种纳米晶陶瓷和金属材料的热力学性能提供了新的研究机会。该项目反映了加州大学戴维斯分校的多学科合作，涉及材料科学、化学和地质学的教师、研究人员和学生。这个新设施将大大加强目前由美国国家科学基金会支持的研究项目，以表征纳米晶体陶瓷（Al2O3, AlN, Si3N4, SiC）和金属（W, Fe, Ni），以及各种纳米复合材料（Al2O3- SiC, Al2O3- zro2， Al2O3-金刚石，Si3N4-SiC, Ni-Al2O3）。新的研究需要立方砧装置的大样本量能力，包括拉伸强度和断裂韧性测量，以及通过溶液和高温量热法测定焓。我们预计这些研究的结果将从根本上有助于我们对纳米晶体结构、机械和热力学性能的理解，以及对最终大规模制造耐用陶瓷复合材料和技术应用的整体材料至关重要的加工参数

9704237 Lesher This award provides support to acquire equipment for the fabrication of large volume parts of materials with nanocrystalline microstructure for mechanical testing and thermodynamic studies. The backbone of this new fabrication system will be the cubic-anvil apparatus. The multianvil payload isdriven by a 1000-ton uniaxial hydraulic press equipped with automated pressure and temperature control for tailored processing. This equipment is unique in combining ultrahigh pressure (up to 5 Gpa) and large sample capacity (5-10 cc) of the payload with resistance and pulsing direct current heating adapted from current plasma activated sintering systems. The recovery of large nanocrystalline samples using this apparatus offers new research opportunities to examine sintering behavior, to determine mechanical properties, and to characterize thermodynamic properties of a wide range of nanocrystalline ceramic and metallic materials. %%% This project reflects a multidisciplinary collaboration on the UC Davis campus involving faculty, researchers and students in materials science, chemistry, and geology. This new facility will greatly enhance research programs currently supported by NSF to characterize nanocrystalline ceramics (Al2O3, AlN, Si3N4, SiC) and metals (W, Fe, Ni), and various nanocomposites (Al2O3-Sic, Al2O3-ZrO2, Al2O3-diamond, Si3N4-SiC, Ni-Al2O3). New investigations requiring the large sample volume capabilities of the cubic-anvil apparatus will include tensile strength and fracture toughness measurements, and enthalpy determinations by solution and high temperature calorimetry. We anticipate the results of these studies will contribute fundamentally to our understanding of nanocrystalline structures, mechanical and thermodynamic properties, as well as processing parameters essential to the eventual development of large-scale fabrication of durable ceramic composites and monoliths for technological applications ***