Microstructural Characterization Methods of PEMFC Electrode Materials

2016 ◽  
pp. 251-294
Keyword(s):  
Electrode Materials ◽  
Microstructural Characterization ◽  
Characterization Methods

Microstructural Characterization Methods for Magnetic Thin Films

1999 ◽  
Vol 562 ◽  
Author(s):  
J. E. Wittig ◽  
J. Bentley ◽  
T. P. Nolan
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Microstructural Characterization ◽  
Magnetic Thin Films ◽  
Complete Analysis ◽  
Structure Property ◽  
Characterization Methods ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
20 Nm

ABSTRACTMicrostructural characterization is key to determining the structure-property-processing relationships required to optimize the performance of magnetic thin films for longitudinal magnetic recording. Since the grain size of modem recording media is on the order of 10 to 20 nm, only high-resolution characterization methods such as transmission electron microscopy (TEM) can accurately describe the microstructure. Complete analysis requires a combination of conventional and high-resolution TEM imaging with analytical methods such as energy dispersivespectroscopy and energy-filtered TEM imaging. This paper provides examples from CoCr(Pt,Ta) alloys that reveal the strengths and limitations of these characterization methods as they apply to microstructural characterization of magnetic thin films.

Characterization and Mitigation of Spark Plug Electrode Erosion in Natural Gas and Automotive Engine Applications

2007 ◽  
Author(s):  
H. T. Lin ◽  
M. P. Brady ◽  
M. D. Kass ◽  
T. J. Theiss ◽  
N. Domingo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Oxidation Resistance ◽  
Electrode Materials ◽  
Elevated Temperatures ◽  
Microstructural Characterization ◽  
Electrode Erosion ◽  
Automotive Engine ◽  
Reciprocating Engine ◽  
Spark Plug ◽  
Early Results

Microstructural characterization was conducted for laboratory gasoline and natural gas reciprocating engine tested spark plug electrodes made from a range of model, developmental, and commercially available electrode alloys. These alloys were selected to explore the effects of differing electrode alloy thermal, chemical, and mechanical characteristics on erosion resistance, and were tested with and without sparking surface alloy insert pads (platinum group and novel Cr-based alloys). Extensive internal oxidation and cracking were observed in both gasoline and natural gas engine tests, indicative of an inherent degree of susceptibility of currently-used electrode materials when heated to elevated temperatures, no matter what the ignition conditions. Highly-alloyed heat-resistant alloys with excellent oxidation resistance in many high-temperature environments suffered from increased rates of erosion, as the gains in oxidation resistance appear to have been offset by hotter running temperatures resulting from decreased electrode alloy thermal conductivity. Promising early results were obtained with a novel Cr-6MgO-0.5Ti-0.3La2O3 insert pad electrode alloy, investigated as an alternative to Pt- or Ir- base alloys, which showed little erosion and good resistance to cracking and oxidation.

scholarly journals Micromechanical behaviors related to confined deformation in pure titanium

2020 ◽  
Vol 321 ◽  
pp. 12018
Author(s):  
Runguang Li ◽  
Youkang Wang ◽  
Xiaojing Liu ◽  
Shilei Li ◽  
Qing Tan ◽  
...  
Keyword(s):  
Shear Banding ◽  
Pure Titanium ◽  
Microstructural Characterization ◽  
High Energy ◽  
Mechanical Twinning ◽  
Uniaxial Tensile ◽  
Good Resolution ◽  
Stress Concentrations ◽  
Complex Deformation ◽  
Characterization Methods

Confined deformation, e.g. mechanical twinning, shear banding, and Lüders banding, etc. was extensively observed in metals and alloys with low stacking-fault energies, especially under complex loadings, governing the mechanical properties. It is often accompanied with gradient microstructures to accommodate the stress concentrations. Understanding the micromechanical behaviors of structural materials having confined deformation is important for evaluating the structural stabilities of engineering components. Synchrotron-based techniques provide powerful tools for multiscale microstructural characterization owing to their good resolution in real/reciprocal space, fast data collection/processing and flexible application scenarios. In this paper, the synchrotron-based high-energy X-ray diffraction (HE-XRD) and microdiffraction (μXRD) techniques in combination with traditional characterization methods are used to reveal the deformational gradient structures/stresses under different loading modes in multiscale. The structure/stress gradients induced by laser shot peening treatment and the deformation twins generated during uniaxial tensile loading in pure titanium were systematically studied by HE-XRD and μXRD, in order to elucidate the accommodating role of the deformational structures subjected to various confined scenarios. The new finding regarding the micromechanical behaviors related to confined deformation contributes to the in-depth understanding of related complex deformation behaviors.

scholarly journals Construction of MoO3/MoSe2 nanocomposite based gas sensor for low detection limit trimethylamine sensing at room temperature

2021 ◽  
Author(s):  
Lanjuan Zhou ◽  
Qian Mi ◽  
Yingbo Jin ◽  
Tingting Li ◽  
Dongzhi Zhang
Keyword(s):  
Detection Limit ◽  
Gas Sensor ◽  
Room Temperature ◽  
Gas Sensing ◽  
Microstructural Characterization ◽  
Honeycomb Structure ◽  
Gas Sensitivity ◽  
Characterization Methods ◽  
Low Detection Limit ◽  
Sensing Performance

Abstract In this paper, MoO3/MoSe2 n-n heterostructure was constructed for fabricating trimethylamine (TMA) gas sensor by an improved hydrothermal and spin-coating method. The surface morphology and microstructure of the prepared materials were analyzed by XRD, XPS, SEM and TEM characterization methods. The microstructural characterization results demonstrated that the MoO3/MoSe2 heterostructure had been successfully synthesized, in which the MoSe2 had a flower-shaped structure, and MoO3 had a rod-shaped structure. At the same time, the MoSe2 surface exhibited periodic honeycomb structure. The gas-sensitivity experimental results showed that the proposed MoO3/MoSe2 sensor had excellent TMA sensing performance at room temperature, including high response capability, low detection limit (20 ppb), short response/recovery time (12 s/19 s), long-term stability, good repeatability and outstanding selectivity. The heterostructure of MoO3/MoSe2 had made outstanding contributions to the enhanced TMA gas sensing performance at room temperature.

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