Infrared Spectroscopy of Molten LiCl−KCl under Hydrogen Gas Atmosphere

2004 ◽  
Vol 108 (21) ◽  
pp. 4567-4569 ◽  
Author(s):  
Hironori Nakajima ◽  
Toshiyuki Nohira ◽  
Yasuhiko Ito
Keyword(s):  
Infrared Spectroscopy ◽  
Hydrogen Gas ◽  
Gas Atmosphere

scholarly journals Stacking Fault Energy in Relation to Hydrogen Environment Embrittlement of Metastable Austenitic Stainless CrNi-Steels

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1170
Author(s):  
Robert Fussik ◽  
Gero Egels ◽  
Werner Theisen ◽  
Sebastian Weber
Keyword(s):  
Phase Transformation ◽  
Intermediate Stage ◽  
Tensile Tests ◽  
Stacking Fault ◽  
Hydrogen Gas ◽  
Stacking Fault Energy ◽  
Austenitic Steels ◽  
Aisi 304L ◽  
Hydrogen Environment ◽  
Gas Atmosphere

Metastable austenitic steels react to plastic deformation with a thermally and/or mechanically induced martensitic phase transformation. The martensitic transformation to α’-martensite can take place directly or indirectly via the intermediate stage of ε-martensite from the single-phase austenite. This effect is influenced by the stacking fault energy (SFE) of austenitic steels. An SFE < 20 mJ/m2 is known to promote indirect conversion, while an SFE > 20 mJ/m2 promotes the direct conversion of austenite into α’-martensite. This relationship has thus far not been considered in relation to the hydrogen environment embrittlement (HEE) of metastable austenitic CrNi steels. To gain new insights into HEE under consideration of the SFE and martensite formation of metastable CrNi steels, tensile tests were carried out in this study at room temperature in an air environment and in a hydrogen gas atmosphere with a pressure of p = 10 MPa. These tests were conducted on a conventionally produced alloy AISI 304L and a laboratory-scale modification of this alloy. In terms of metal physics, the steels under consideration differed in the value of the experimentally determined SFE. The SFE of the AISI 304L was 22.7 ± 0.8 mJ/m2 and the SFE of the 304 mod alloy was 18.7 ± 0.4 mJ/m2. The tensile specimens tested in air revealed a direct γàα’ conversion for AISI 304L and an indirect γàεàα’ conversion for 304mod. From the results it could be deduced that the indirect phase transformation is responsible for a significant increase in the content of deformation-induced α’-martensite due to a reduction of the SFE value below 20 mJ/m2 in hydrogen gas atmosphere.

Buried Metal Deposition on Gallium Arsenide by Laser-Induced Thermochemical Reaction

1987 ◽  
Vol 101 ◽  
Author(s):  
Jun Tokuda ◽  
Mikio Takai ◽  
Kenji Gamo ◽  
Susumu Namba
Keyword(s):  
Gallium Arsenide ◽  
Tin Oxide ◽  
Tin Dioxide ◽  
Density Ratio ◽  
Hydrogen Gas ◽  
Outer Side ◽  
Gas Atmosphere ◽  
Oxide Deposition ◽  
Ion Laser ◽  
Deposited Film

ABSTRACTTin oxide deposition was performed by focused argon ion laser irradiation in a tin tetrachloride gas atmosphere. Etching of gallium arsenide and tin oxide deposition were observed in a single scan of a laser beam under specific conditions. The center of the irradiated area was etched and then covered with deposit. Density ratio of 0/Sn obtained from the deposit by AES measurements was about 1.4 - 1.6. Additional hydrogen gas in ambient SnCl4 gas reduced both tin oxide deposition and gallium arsenide etching. Deposition, at first, occurred at the outer side of the irradiated area and gallium arsenide etching occurred at the center of it. The amount of deposit depends on beam dwell time. Additional oxygen in ambient SnCl4 gas improved deposited film quality: the deposited film with additional oxygen proved to be tin dioxide, which is an conductor.

BN/NiO nanocomposites: Structural, defect chemistry and electrical properties in hydrogen gas atmosphere

2020 ◽  
Vol 46 (16) ◽  
pp. 26233-26237
Author(s):  
Kulwinder Singh ◽  
Manjot Kaur ◽  
Ishant Chauhan ◽  
Amit Awasthi ◽  
Manjeet Kumar ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Structural Defect ◽  
Defect Chemistry ◽  
Hydrogen Gas ◽  
Gas Atmosphere

scholarly journals Production of Fe-C Alloys through Reduction and Sintering of Cementite Powders in Hydrogen Gas Atmosphere

2007 ◽  
Vol 93 (3) ◽  
pp. 228-233 ◽  
Author(s):  
Koichi NAKASHIMA ◽  
Nobuaki OUCHIDA ◽  
Makoto EGASHIRA ◽  
Toshihiro TSUCHIYAMA ◽  
Setsuo TAKAKI
Keyword(s):  
Hydrogen Gas ◽  
Gas Atmosphere

Theoretical Analysis of Porosity in an Ordered Porous Copper Fabricated by Continuous Unidirectional Solidification

2018 ◽  
Vol 933 ◽  
pp. 136-141
Author(s):  
Rong Cao ◽  
Qing Lin Jin
Keyword(s):  
High Pressure ◽  
Theoretical Model ◽  
Theoretical Analysis ◽  
Processing Parameters ◽  
Unidirectional Solidification ◽  
Hydrogen Gas ◽  
Porous Copper ◽  
Gas Atmosphere ◽  
Ordered Porous ◽  
Good Agreement

Ordered porous copper with elongated pores has been fabricated by a continuous unidirectional solidification method in a hydrogen gas atmosphere with high pressure. The porosity of the ordered porous copper is significantly affected by the pressure of hydrogen. A theoretical model is developed to get the relation between the porosity and the processing parameters. The calculated values are in good agreement with the experimental results. Key words: Unidirectional solidification; Ordered porous copper; Porosity; Modeling.

Hydrogen Passivation of Er and Si Nanocrystallites in Er-doped SiO2 - Increase in Photoluminescence-

2004 ◽  
Vol 832 ◽  
Author(s):  
N. Fukata ◽  
C. Li ◽  
H. Uematsu ◽  
T. Arai ◽  
T. Makimura ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Signal Intensity ◽  
Hydrogen Gas ◽  
Hydrogen Passivation ◽  
Si Substrate ◽  
Gas Atmosphere ◽  
Oxygen Gas ◽  
Pl Intensity ◽  
Er Doped ◽  
Si Nanocrystallites

ABSTRACTHydrogen passivation effect on the enhancement of photoluminescence (PL) of Er ions in SiO2 films contained Si nanocrystallites (nc-Si) has been investigated. Er-doped SiO2 films were fabricated by laser ablation of Er-deposited Si substrate in oxygen gas atmosphere. The PL intensity of Er ions and nc-Si were increased by hydrogen gas treatments, while ESR signal intensity of residual defects located at the interfaces between nc-Si and SiO2 was decreased. These results indicate that hydrogen passivation of residual defects is useful for the enhancement of the Er PL.

3220 Tribological properties of zirconium alloys in a hydrogen gas atmosphere

2008 ◽  
Vol 2008.4 (0) ◽  
pp. 137-138
Author(s):  
Takashi MURAKAMI ◽  
Hiroki MANO ◽  
Shinya SASAKI ◽  
Joichi SUGIMURA
Keyword(s):  
Tribological Properties ◽  
Zirconium Alloys ◽  
Hydrogen Gas ◽  
Gas Atmosphere

Electrochemical Studies on the Passivation Behavior of Cu-Ni-Fe Alloy in Borate Buffer Solution at pH 8.4

2011 ◽  
Vol 399-401 ◽  
pp. 2067-2071
Author(s):  
Qiong Yu Zhou ◽  
Yi Wang ◽  
Qing Dong Zhong
Keyword(s):  
Passive Film ◽  
Heating Temperature ◽  
Alloy Layer ◽  
Hydrogen Gas ◽  
Borate Buffer ◽  
Borate Buffer Solution ◽  
Buffer Solution ◽  
Mixed Powder ◽  
Gas Atmosphere ◽  
Semiconductor Properties

Cu-Ni-Fe alloy-layer was prepared by the method of copper oxide- nickel oxide mixed powder deposited on the surface of mild steel samples and then treated under high temperature and hydrogen gas atmosphere. Polarization techniques and Mott-Schottky analysis in conjunction with the point defect model (PDM) have been used to investigate the semiconductor properties of the passive films formed on the surface of Cu-Ni-Fe alloy layer in borate buffer solution at pH 8.4. The results showed that the passive film formed on the surface was more compact, highly protective with higher heating temperature. Carriers density and vacancies diffusion coefficient of the passive film formed on Cu-Ni-Fe alloys decreased with higher heating temperature. The vacancies diffusivity is about magnitude of 10-20m2•s-1 in borate buffer solution at pH 8.4.

Positive Effect of Hydrogen Treatment in Titanium Ti-6Al-4V Alloy

2011 ◽  
Vol 183 ◽  
pp. 179-184 ◽  
Author(s):  
Maria Sozańska
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Titanium Hydride ◽  
High Stress ◽  
Absorption Capacity ◽  
Hydrogen Gas ◽  
Hydrogen Treatment ◽  
Two Phase ◽  
Deformation Phase ◽  
Gas Atmosphere

Positive nature of the effects of hydrogen on the properties of titanium alloys is manifested in the high temperature hydrogen treatment (HTM - Hydrogen Treatment of Materials), where hydrogen is temporary alloying component. This is possible because of the high values ​​of diffusion coefficients can be easily introduced into the titanium and it just as easily removed. Titanium and its alloys exhibit a high affinity for hydrogen absorption capacity, about 60% at. hydrogen at 600 °C. The hydrogen in titanium alloy is present in the form – an interstitial solution or titanium hydride. Since the specific volume of titanium hydride is about 13 ÷ 17% higher compared to α phase, it is high stress in the crystal lattice of this phase leads to local plastic deformation and large deformation phase. The paper presents the results of the possibilities of hydrogen using as a temporary alloying element in Ti-6Al-4V alloy. Treatment of hydrogen alloy consisted of three stages: hydrogenation in hydrogen gas atmosphere at 650 °C, a cyclic hydrogen-treatment (3 cycles 650 °C or 950 °C to 250 °C) and a dehydrogenation in vacuum (550 °C). It was shown that hydrogen affects appreciably changes the microstructure of surface layer of the tested titanium alloy. The aim of this study is thus to determine the effect of hydrogen on the two-phase microstructure, hardness, and corrosion resistance of the titanium alloy Ti-6Al-4V due to high-temperature hydrogen treatment.

Characterization of Hydroxyapatite Containing of Titanium Hydride Sintered Body by Nano Size Powder

2013 ◽  
Vol 761 ◽  
pp. 135-139
Author(s):  
Kazuki Ishiwata ◽  
Kazumasa Tawara ◽  
Junichi Matsushita
Keyword(s):  
Titanium Hydride ◽  
Hydrogen Gas ◽  
Artificial Bone ◽  
Happy Life ◽  
Gas Atmosphere ◽  
Sbf Solution ◽  
Advanced Biomaterials ◽  
Dental Applications

The material study on bioactivitying artificial bone is lacking results for improve the quality of life (QOL) for individuals to fulfill their happy life in the society, which requires artificial bone to be replaced with neonatal bone by absorbing, regenerating the bone, which is not possible. Hydroxyapatite Ca10(PO4)6(OH)2, (HAp) has excellent biomaterial for biomedical and dental applications because of its superior properties. However, HAp had poor mechanical properties such as low hardness and fracture toughness. In this study, HAp containing titanium and titanium hydride (TiH2) sintered bodies were studied in order to investigate the possibility of its advanced biomaterials application. The nano particle size starting powders were milled by using mortar and muddler equipment. The sintered bodies were prepared by pressureless sintering at argon-hydrogen gas atmosphere. The samples were evaluated for bioactive performance by using simulated body fluid (SBF) solution for. The HAp-Ti, the HAp-TiH2 composite material is attractive as a bioceramics compared with HAp ceramics.

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