Enhanced high temperature hydrogen permeation characteristics of V–Ni alloy membranes containing a trace amount of yttrium

2016 ◽  
Vol 116 ◽  
pp. 122-126 ◽  
Author(s):  
Ju-Young Oh ◽  
Won-Seok Ko ◽  
Jin-Yoo Suh ◽  
Youg-Su Lee ◽  
Byeong-Joo Lee ◽  
...  
Keyword(s):  
High Temperature ◽  
Trace Amount ◽  
Hydrogen Permeation ◽  
Ni Alloy

Pure Ni and Pd-Ni Alloy Membranes Prepared by Electroless Plating for Hydrogen Separation

2011 ◽  
Vol 179-180 ◽  
pp. 1309-1313 ◽  
Author(s):  
Xiao Liang Zhang ◽  
Xu Feng Xie ◽  
Yan Huang
Keyword(s):  
Electroless Plating ◽  
Hydrogen Permeation ◽  
Hydrogen Permeability ◽  
Composite Membranes ◽  
Hydrogen Separation ◽  
High Hydrogen ◽  
Ni Alloy ◽  
Plating Method ◽  
Fcc Phase ◽  
The Ideal

Pd-based composite membranes are the attractive membrane materials for hydrogen separation due to their high hydrogen permeability and infinite permselectivity. Thin pure Ni and Pd-Ni alloy membranes with high hydrogen permeation were prepared by the electroless plating method. It is difficult to prepare the dense pure Ni membranes with 1-2 μm thickness for hydrogen separation. However, Pd-Ni alloy membranes with several micrometers thickness showed good permeation performance. Hydrogen permeance of the Pd95Ni5 alloy membrane with fcc phase up to 3.1×10-6 mol/m2 s Pa and the ideal permselectivity over 600 were obtained at 773 K.

Recrystallization Characteristics of Ti-50.9at%Ni Alloy Processed by Equal Channel Angular Extrusion

2007 ◽  
Vol 26-28 ◽  
pp. 385-388 ◽  
Author(s):  
Zhi Guo Fan ◽  
Chao Ying Xie
Keyword(s):  
High Temperature ◽  
Optical Microscopy ◽  
Equal Channel Angular Extrusion ◽  
Recrystallization Process ◽  
Recrystallization Behavior ◽  
Ni Alloy ◽  
Coarse Grains ◽  
Angular Extrusion

The initial coarse grains of Ti-50.9at%Ni alloy were refined into submicron grains, small than 0.5 um in size, after eight passes Equal Channel Angular Extrusion (ECAE) at 500°C. Optical microscopy and high temperature DSC tests were applied to investigate recrystallization behavior. It is found that the recrystallization start (Rs) and recrystallization peak (Rp) temperatures of Ti-50.9at%Ni specimens processed by eight passes ECAE are lower than that of the samples processed by one pass ECAE. Ti-50.9at%Ni specimens processed by eight passes ECAE with submicron grains are characterized by higher stability and need less energy to finish recrystallization process.

Hydrogen Diffusion Coefficient during Hydrogen Permeation through Nb-Based Hydrogen Permeable Membranes

2009 ◽  
Vol 283-286 ◽  
pp. 225-230 ◽  
Author(s):  
Hiroshi Yukawa ◽  
G.X. Zhang ◽  
N. Watanabe ◽  
Masahiko Morinaga ◽  
T. Nambu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffusion Coefficient ◽  
High Temperature ◽  
Solid Solutions ◽  
Diffusion Coefficients ◽  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Pure Niobium ◽  
Hydrogen Diffusion Coefficient

The hydrogen diffusion coefficients are investigated during the hydrogen permeation through Nb-based hydrogen permeable membranes at high temperature. It is found that the hydrogen diffusion coefficient for pure niobium under practical conditions is much lower than the reported values measured for dilute hydrogen solid solutions. Surprisingly, the hydrogen diffusion is found to be faster in Pd-Ag alloy with fcc crystal structure than in pure niobium with bcc crystal structure at 773K during the hydrogen permeation. It is also found that the addition of Ru or W into niobium increases the hydrogen diffusion coefficient under the practical conditions.

Fabrications and Evaluations of Hydrogen Permeation on TiN-5wt%Ni Membrane by Spark Plasma Sintering

2009 ◽  
Vol 620-622 ◽  
pp. 13-16
Author(s):  
Kyeong Il Kim ◽  
Tae Whan Hong
Keyword(s):  
High Temperature ◽  
Hydrogen Embrittlement ◽  
Spark Plasma Sintering ◽  
Fossil Fuel ◽  
Hydrogen Permeation ◽  
Pd Membrane ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Hydrogen Selectivity ◽  
Vibration Mill

Many laboratories have researched membrane for gasification of coal technique, separating hydrogen from fossil fuel. In general, Pd membrane of separating hydrogen is very good a property of hydrogen selectivity on high temperature, but it has some problems, hydrogen embrittlement and costly material. So, we need some materials of good properties about hydrogen selectivity instead of Pd. In this research, we fabricate membrane for hydrogen permeation, that is great in resistance to acids and chemically steady TiN. Our laboratory investigated about hydrogen selectivity. TiN powder is milled 30, 60 and 240 minutes by vibration mill, respectively. After than the samples put in operate spark plasma sintering. We analyze XRD, SEM, BET and TG/DSC. Also, in this research take an inspect hydrogen selectivity by ourselves manufactured Sievert’s type hydrogen permeation membrane equipment.

Advanced Coatings on High Temperature Applications

2006 ◽  
Vol 522-523 ◽  
pp. 1-14 ◽  
Author(s):  
Toshio Narita ◽  
Takeshi Izumi ◽  
Takumi Nishimoto ◽  
Yoshimitsu Shibata ◽  
Kemas Zaini Thosin ◽  
...  
Keyword(s):  
High Temperature ◽  
Diffusion Barrier ◽  
Layer Structure ◽  
Diffusion Coating ◽  
Alloy Layer ◽  
Outward Diffusion ◽  
Hastelloy X ◽  
Alloy Substrate ◽  
Barrier Coating ◽  
Ni Alloy

To suppress interdiffusion between the coating and alloy substrate in addition to ensuring slow oxide growth at very high temperatures advanced coatings were developed, and they were classified into four groups, (1) the diffusion barrier coating with a duplex layer structure, an inner σ−(Re-Cr-Ni) phase as a diffusion barrier and outer Ni aluminides as an aluminum reservoir formed on a Ni based superalloy, Hastelloy X, and Nb-based alloy. (2) the up-hill diffusion coating with a duplex layer structure, an inner TiAl2 + L12 and an outer β-NiAl formed on TiAl intermetallic and Ti-based heat resistant alloys by the Ni-plating followed by high Al-activity pack cementation. (3) the chemical barrier coating with a duplex layer structure, an inner* γ + β + Laves three phases mixture as a chemical diffusion barrier and an outer Al-rich γ-TiAl as an Al reservoir formed by the two step Cr / Al pack process. (4) the self-formed coating with the duplex structure, an inner α-Cr layer as a diffusion barrier and an outer β-NiAl as an Al-reservoir on Ni-(2050)at% Cr alloy changed from the δ-Ni2Al3 coating during oxidation at high temperature. The oxidation properties of the coated alloys were investigated at temperatures between 1173 and 1573K in air for up to 1,000 hrs (10,000 hrs for the up-hill diffusion coating). In the diffusion barrier coating the Re-Cr-Ni alloy layer was stable, existing between the Ni-based superalloy (or Hastelloy X) and Ni aluminides containing 1250at%Al when oxidized at 1423K for up to 1800ks. It was found that the Re-Cr-Ni alloy layer acts as a diffusion barrier for both the inward diffusion of Al and outward diffusion of alloying elements in the alloy substrate. In the chemical barrier coating both the TiAl2 outermost and Al-rich γ-TiAl outer layers maintained high Al contents, forming a protective Al2O3 scale, and it seems that the inner, γ, β, Laves three phase mixture layer suppresses mutual diffusion between the alloy substrate and the outer/outermost layers.

Hydrogen permeation characteristics of palladium-plated VNi alloy membranes

1991 ◽  
Vol 172-174 ◽  
pp. 727-731 ◽  
Author(s):  
M. Amano ◽  
M. Komaki ◽  
C. Nishimura
Keyword(s):  
Hydrogen Permeation ◽  
Ni Alloy

Ni and Ni-Alloy Tapes with a Very Strong Cube Texture as Substrates for High Temperature Superconducting Tapes

2002 ◽  
Vol 408-412 ◽  
pp. 1561-1566 ◽  
Author(s):  
V.S. Sarma ◽  
B. De Boer ◽  
N. Reger ◽  
J. Eickemeyer ◽  
R. Opitz ◽  
...  
Keyword(s):  
High Temperature ◽  
Cube Texture ◽  
Superconducting Tapes ◽  
High Temperature Superconducting ◽  
Ni Alloy
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