Fundamental Understanding of the Dissolution of Oxide Film on Ti Powder and the Unique Scavenging Feature by LaB6

2017 ◽  
Vol 49 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Y. F. Yang ◽  
M. Qian
Keyword(s):  
Oxide Film ◽  
Fundamental Understanding ◽  
Ti Powder

Towards an atomic-scale understanding of oxide film in the Ti powder surface

2022 ◽  
Vol 210 ◽  
pp. 114471
Author(s):  
Qiying Tao ◽  
Wangwang Ding ◽  
Gang Chen ◽  
Xuanhui Qu ◽  
Mingli Qin
Keyword(s):  
Oxide Film ◽  
Atomic Scale ◽  
Powder Surface ◽  
Ti Powder

Deposited emulsion particles in the pores of aluminum oxide film

1978 ◽  
Vol 36 (1) ◽  
pp. 450-451
Author(s):  
Michio Ashida ◽  
Yasukiyo Ueda
Keyword(s):  
Oxide Film ◽  
Acid Solution ◽  
Barrier Layer ◽  
Colloidal Particles ◽  
Oxalic Acid Solution ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Carbon Replica ◽  
Sectioning Method ◽  
Thin Sectioning

An anodic oxide film is formed on aluminum in an acidic elecrolyte during anodizing. The structure of the oxide film was observed directly by carbon replica method(l) and ultra-thin sectioning method(2). The oxide film consists of barrier layer and porous layer constructed with fine hexagonal cellular structure. The diameter of micro pores and the thickness of barrier layer depend on the applying voltage and electrolyte. Because the dimension of the pore corresponds to that of colloidal particles, many metals deposit in the pores. When the oxide film is treated as anode in emulsion of polyelectrolyte, the emulsion particles migrate onto the film and deposit on it. We investigated the behavior of the emulsion particles during electrodeposition.Aluminum foils (99.3%) were anodized in either 0.25M oxalic acid solution at 30°C or 3M sulfuric acid solution at 20°C. After washing with distilled water, the oxide films used as anode were coated with emulsion particles by applying voltage of 200V and then they were cured at 190°C for 30 minutes.

Shock consolidation of Ni-Ti alloy powder

1986 ◽  
Vol 44 ◽  
pp. 430-431
Author(s):  
Naresh N. Thadhani ◽  
Thad Vreeland ◽  
Thomas J. Ahrens
Keyword(s):  
Alloy Powder ◽  
Amorphous Material ◽  
Ti Alloy ◽  
Two Phase ◽  
Near Surface ◽  
Optical Micrograph ◽  
Shock Compaction ◽  
Powder Particles ◽  
Ti Powder ◽  
Rapidly Solidified

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.

Strain analysis in composite ceramics

1986 ◽  
Vol 44 ◽  
pp. 494-497
Author(s):  
W. M. Kriven
Keyword(s):  
Strain Field ◽  
Strain Analysis ◽  
Processing Temperature ◽  
Transformation Toughening ◽  
Zirconia Ceramics ◽  
Volume Increase ◽  
Analysis Technique ◽  
Fundamental Understanding ◽  
Contrast Analysis ◽  
Elastic Strain Field

Significant progress towards a fundamental understanding of transformation toughening in composite zirconia ceramics was made possible by the application of a TEM contrast analysis technique for imaging elastic strains. Spherical zirconia particles dispersed in a large-grained alumina matrix were examined by 1 MeV HVEM to simulate bulk conditions. A thermal contraction mismatch arose on cooling from the processing temperature of 1500°C to RT. Tetragonal ZrO2 contracted amisotropically with α(ct) = 16 X 10-6/°C and α(at) = 11 X 10-6/°C and faster than Al2O3 which contracted relatively isotropically at α = 8 X 10-6/°C. A volume increase of +4.9% accompanied the transformation to monoclinic symmetry at room temperature. The elastic strain field surrounding a particle before transformation was 3-dimensionally correlated with the internal crystallographic orientation of the particle and with the strain field after transformation. The aim of this paper is to theoretically and experimentally describe this technique using the ZrO2 as an example and thereby to illustrate the experimental requirements Tor such an analysis in other systems.

Progress and perspectives on halide lithium conductors for all-solid-state lithium batteries

2020 ◽  
Vol 13 (5) ◽  
pp. 1429-1461 ◽  
Author(s):  
Xiaona Li ◽  
Jianwen Liang ◽  
Xiaofei Yang ◽  
Keegan R. Adair ◽  
Changhong Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Solid State ◽  
Lithium Batteries ◽  
Electrochemical Stability ◽  
Superionic Conductors ◽  
Fundamental Understanding ◽  
Potential Applications ◽  
Synthesis Routes

This review focuses on fundamental understanding, various synthesis routes, chemical/electrochemical stability of halide-based lithium superionic conductors, and their potential applications in energy storage as well as related challenges.

Predictive tool for frictional performance of piston ring-pack/liner conjunction

2019 ◽  
Vol 13 (3) ◽  
pp. 5513-5527
Author(s):  
J. W. Tee ◽  
S. H. Hamdan ◽  
W. W. F. Chong
Keyword(s):  
Film Thickness ◽  
Mathematical Models ◽  
Piston Ring ◽  
Published Data ◽  
Predictive Tool ◽  
Frictional Losses ◽  
Fundamental Understanding ◽  
Minimum Film Thickness ◽  
Piston Ring Pack ◽  
Ring Pack

Fundamental understanding of piston ring-pack lubrication is essential in reducing engine friction. This is because a substantial portion of engine frictional losses come from piston-ring assembly. Hence, this study investigates the tribological impact of different piston ring profiles towards engine in-cylinder friction. Mathematical models are derived from Reynolds equation by using Reynolds’ boundary conditions to generate the contact pressure distribution along the complete piston ring-pack/liner conjunction. The predicted minimum film thickness is then used to predict the friction generated between the piston ring-pack and the engine cylinder liner. The engine in-cylinder friction is predicted using Greenwood and Williamson’s rough surface contact model. The model considers both the boundary friction and the viscous friction components. These mathematical models are integrated to simulate the total engine in-cylinder friction originating from the studied piston ring-pack for a complete engine cycle. The predicted minimum film thickness and frictional properties from the current models are shown to correlate reasonably with the published data. Hence, the proposed mathematical approach prepares a simplistic platform in predicting frictional losses of piston ring-pack/liner conjunction, allowing for an improved fundamental understanding of the parasitic losses in an internal combustion engine.

Surface Microstructure Evolution Upon Silicidation of Ni(Pt) and the Different Responses to Metal Etch

2013 ◽  
Author(s):  
Wentao Qin ◽  
Dorai Iyer ◽  
Jim Morgan ◽  
Carroll Casteel ◽  
Robert Watkins ◽  
...  
Keyword(s):  
Thin Film ◽  
Oxide Film ◽  
Microstructure Evolution ◽  
Depth Profiling ◽  
Surface Microstructure ◽  
The Difference ◽  
Surface Microstructures ◽  
Pt Films

Abstract Ni(5 at.%Pt ) films were silicided at a temperature below 400 °C and at 550 °C. The two silicidation temperatures had produced different responses to the subsequent metal etch. Catastrophic removal of the silicide was seen with the low silicidation temperature, while the desired etch selectivity was achieved with the high silicidation temperature. The surface microstructures developed were characterized with TEM and Auger depth profiling. The data correlate with both silicidation temperatures and ultimately the difference in the response to the metal etch. With the high silicidation temperature, there existed a thin Si-oxide film that was close to the surface and embedded with particles which contain metals. This thin film is expected to contribute significantly to the desired etch selectivity. The formation of this layer is interpreted thermodynamically.

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