Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The mechanical properties of two SiC whisker/Al2O3 matrix composites were investigated as a function of whisker type. Composites were produced with both Silar-SC-9 and Tateho-SCW-1-S whiskers. The composites produced with the Silar-SC-9 whiskers exhibited a fracture strength of 641 MPa and a fracture toughness of 8.7…
Vinyl polymerization (in bulk and in solution) of a cyclic oligomer of vinyl-methylsilazane (i.e., 1,3,5-trimelhyl-1,3,5-trivinylcyclotrisilazane) was investigated as a method for preparing polymeric precursors to silicon carbide and silicon nitride. After synthesis, the polymers were characterized by size exclusion c…
Ceramic matrix composites were investigated for structural and thermal applications in high efficiency and environmental conscious fusion energy systems. In order to up-grade their low activation characteristics, thermal conductivity and high temperature properties, the crystallized Si-Al-C fiber (Tyranno-SA) and pyro…
Abstract Micron‐scale platelet (Na, K)NbO 3 particles were synthesized from the platelet precursor K 4 Nb 6 O 17 in a KCl medium using a topochemical method . The salt took part in the reaction and affected the composition of the products. Stoichiometric (Na 0.5 K 0.5 )NbO 3 could be accurately synthesized by controll…
It was described in the previous paper that fully dense TiB2-20 wt% (2 mol% Y2O3-ZrO-) sintered bodies were fabricated by glass encapsulation HIP (1600°C, 200 MPa, 2 h), and their 3-pt. bending strength was as high as 1200 MPa. In this material, grain growth occurred during sintering; the grain sizes of TiB2 and ZrO2i…
Abstract A new approach for determination of refractive index dispersion n(λ) (the real part of the complex refractive index) and thickness d of thin films of negligible absorption and weak dispersion is proposed. The calculation procedure is based on determination of the phase thickness of the film in the spectral re…
Armor-grade B4C and WC cylinders (25.4 mm × 25.4 mm) were impacted with WC-6Co (6 wt.% Co) spheres (6.35 mm diameter) at velocities between 100 m/s and 400 m/s. The recovered cylinders were subsequently sectioned and metallographically-prepared to reveal the dominant sub-surface damage types and change in damage sever…
Processing additives and conditions allow a wide variation in microstructures and mechanical properties for SiC-based ceramics prepared by hot pressing. Five experimental materials with a wide variety of microstructures and mechanical properties were fabricated and compared with SiC-N, a commercially available materia…
Computational ceramic armor models are reviewed, with an emphasis on a historical perspective. Some discussion concerning the current state of the art is provided, including a summary of issues concerning the strength of in-situ comminuted ceramic.
Silicone polymers, due to their high lubricity and good spreading properties, are widely used in industrial applications. Being insoluble in water and most hydrocarbons, a common mode of delivering silicones is in the form of emulsions. To stabilize silicones in the emulsion form more efficiently, it is useful to unde…
An x-ray powder diffraction study of polycrystalline Dy was performed over the temperature interval from 5 to $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in applied magnetic fields up to $40\phantom{\rule{0.3em}{0ex}}\mathrm{kOe}$. A complex first-order magnetostructural transformation, which occurs below $\ensuremath{…
Nicalon™ fiber-reinforced aluminum oxide and aluminum nitride matrix composites were fabricated using directed metal oxidation technology. Flexural strengths and fracture toughnesses of the Nicalon™ / Al2O3 composites were measured between 21°C and 1200°C. The removal of residual aluminum from the pore network in the…
This study investigated the influence of growth conditions on the microstructure and mechanical behavior of fibers of aluminum oxide, A12O3, and zirconium oxide, ZrO2, eutectic grown by the Edge defined-Film fed-Growth (EFG) method. The results indicated a dependence of microstructure on growth rate, with no strong co…
Alumina and alumina matrix composites containing 5 to 20 volume percent of multi-wall carbon nanotubes (MWNT) were fabricated by hot pressing in Ar atmosphere at 1300°C for 1h with 60 MPa of applied pressure. A powder of α-phase alumina, with 44 nm mean diameter, and arc-derived MWNT were used for these experiments. T…
In this study for the first time the effect of high-pressure CO2 on the coacervation of alpha-elastin was investigated using analytical techniques including light spectroscopy and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic imaging and circular dichroism (CD) spectroscopy. The coace…
The isotropic–nematic (I–N) phase transition in a system of long straight rigid rods of length k on square lattices is studied by combining Monte Carlo simulations and theoretical analysis. The process is analyzed by comparing the configurational entropy of the system with that corresponding to a fully aligned system,…
In order to improve the fabrication process and the performances of SiC/SiC composites, poly(vinylsilane), which is a new type liquid poly(carbosilane) with significant Si-H functionality, was adopted for a matrix precursor in polymer impregnation and pyrolysis (PIP) process. Since the thermal behavior of a precursor…
An oxide\oxide ceramic matrix composite (CMC) with no interphase at the fiber-matrix interface was characterized under monotonic tensile testing and cyclic tensile loading at 23°C and 1200°C. The effect of room temperature moisture exposure on fatigue behavior was also examined at 1200°C. The composite consisted of 10…
Local magnetic moment formation on edges of graphene is studied using the Hubbard model on a honeycomb lattice. The Coulomb interaction is treated with the mean field approximation. Realistic edges of graphene are composed of zigzag and armchair parts. It is found that, on a zigzag part of length n a larger than 3 a ,…
Macro (Taber) wear tests and especially micro (pin-on-disk) tests performed on Al2O3 and B4C, as a function of varying porosity, show wear increasing exponentially with porosity. Al2O3, which was tested over a much more extensive range of porosity, showed a significant change in the porosity dependence of wear at appr…