Nano Al2O3 Rod Array Structure Produced by Using Internal Oxidation of Dilute Ni(Al) Alloys

2019 ◽  
Vol 3 (14) ◽  
pp. 3-12 ◽  
Author(s):  
Makoto Nanko ◽  
Katsumi Uemura ◽  
Kazuyuki Takeda
Keyword(s):  
Internal Oxidation ◽  
Al Alloys ◽  
Array Structure ◽  
Rod Array

Fabrication of Nanorod Array Structure by Using Aluminizing and Internal Oxidation of Ni with Micro-Channels

2013 ◽  
Vol 761 ◽  
pp. 131-134
Author(s):  
Takeshi Ishizaki ◽  
Dung Thi Mai Do ◽  
Makoto Nanko
Keyword(s):  
Internal Oxidation ◽  
Nanorod Array ◽  
Pack Cementation ◽  
Micro Channel ◽  
Electric Discharge Machining ◽  
Micro Channels ◽  
Channel Surface ◽  
Nano Rods ◽  
Array Structure ◽  
Rod Array

A metallurgical method for preparing oxide nano-rod array structure was developed with internal oxidation of Ni(Al) solid solution obtained by aluminizing Ni with a pack cementation technique. The present method was applied in order to fabricate nano-rod array on the micro-channel surface of microreactor. A micro-channel with 1 mm in depth, 1mm in width and 10 mm in length was fabricated on the Ni disk by an electric discharge machining and electropolishing. The Ni disk with a micro-channel was annealed at 1300°C for 12 h in vacuum. The sample was aluminized by a pack cementation using pack powder mixture consisting of 10 mass% of Ni3Al, 88 mass% of Al2O3 and 2 mass% of NaCl at 1100°C for 12 h in a flow of argon gas. The sample was oxidized from 1000 to 1200°C for 6 h with the Co/CoO buffer. Ni matrix in internally oxidized zone was removed by electropolishing to expose nano-rods. Al2O3 nano-rod array located on the micro-channel surface was successfully fabricated with the proposed technique. Diameter and height of nano-rods were ranged from 100 to 300 nm and from 1.5 to 3 µm, respectively.

The Effects of Stress on the Internal Oxidation of Ni-Cr and Ni-Al Alloys

1997 ◽  
Vol 251-254 ◽  
pp. 341-348 ◽  
Author(s):  
L. Bradley ◽  
G.C. Wood ◽  
F.Howard Stott
Keyword(s):  
Internal Oxidation ◽  
Al Alloys ◽  
Effects Of Stress

scholarly journals Estimating the Internal Oxidation of Ni-Al Alloys

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 48 ◽  
Author(s):  
C.G. Nava-Dino ◽  
A. Martinez-Villafañe
Keyword(s):  
Image Processing ◽  
Optical Microscopy ◽  
Internal Oxidation ◽  
Al Alloys ◽  
Aluminum Concentration ◽  
Al Alloy ◽  
Internal Oxide ◽  
Continuous Precipitation ◽  
X Ray ◽  
Temperature Time

Ni-Al alloys create a cone- shaped figure when there is internal oxide. This behavior was studied by TEM, SEM, X-Ray (XRD), Optical Microscopy and Image Processing. The internal oxide precipitates and its results indicate that this precipitation forms continuous rods in a cone-shaped configuration extending from the surface to the internal oxide front for Ni-Al alloys, whereas for Ni-X (X = Cr, Mo, V, W and Mn) alloys the precipitation is discrete and more irregularly-shaped. Furthermore, in a high atomic percentage (5.18% to 8.67%), the precipitation was rod-like and continuous from the surface to the internal oxide front for all temperature\time conditions. For the Ni-2.47% Al alloy at 800 °C, observations showed a mixture of rod-like and fork like precipitates, whereas after oxidation at 1000 and 1100 °C the precipitation was rod-like and continuous. For the Ni-1.18% Al alloy the aluminum concentration was insufficient for fully continuous precipitation to develop, and the internal oxides were generally acicular-shaped and discontinuous. Images obtained by TEM and, after that, analyzed by image processing allowed us to understand their behavior and the internal oxide patterns.

Internal oxidation of Fe-Al alloys in the ?-phase region

1986 ◽  
Vol 25 (1-2) ◽  
pp. 93-105 ◽  
Author(s):  
Jun Takada ◽  
Sadahiro Yamamoto ◽  
Shiomi Kikuchi ◽  
Masao Adachi
Keyword(s):  
Internal Oxidation ◽  
Phase Region ◽  
Al Alloys

The Oxidation off Iron, Nickel and Cobalt-Base Alloys Containing Aluminum

CORROSION ◽  
1965 ◽  
Vol 21 (10) ◽  
pp. 316-326 ◽  
Author(s):  
W. C. HAGEL
Keyword(s):  
Weight Gain ◽  
Internal Oxidation ◽  
Outer Layer ◽  
Al Alloys ◽  
Reaction Products ◽  
Parabolic Growth ◽  
Iron Nickel ◽  
Α Al2o3 ◽  
Cobalt Base ◽  
Continuous Weight

Abstract By conducting continuous weight-gain measurements from 500 to 1300 C on a variety of Fe-Al, Fe-Cr-Al, Ni-Al and Co-Al alloys in oxygen at 100 torr and examining the reaction products which form, reasons for the enexpected ineffectiveness of preferential aluminum oxidation have been explored. With Fe-4.4 percent Al and Fe-12 percent Al, there are two different regions of parabolic growth- these are associated with the appearance of γ-A12O3 below 900 C and α-Al2O3 above. The latter is normally more protective but possesses a greater tendency for cracking and spalling; adding 24.6 percent chromium promotes its formation at lower temperatures. With Ni-5.0 percent Al, two displaced regions are also found; here, nickel penetrates alumina to provide intermediate NiO · Al2O3 and an outer layer of NiO. With Co-4 percent Al, somewhat less cobalt penetrates γ-Al2O3 to provide CoQ · Al2O3 and an outer layer of Co3O4. When both CoO and α-Al2O3 are stable phases, the latter grows mainly by internal oxidation and offers little protection.

Facile synthesis of bimetallic-based CoMoO4/MoO2/CoP oxidized/phosphides nanorod arrays and electroplated with FeOOH for efficient overall seawater splitting

CrystEngComm ◽  
2021 ◽  
Author(s):  
Ping Yang ◽  
Congcong Jin ◽  
Menglei Ren ◽  
Honglong Xing ◽  
Jianjun Shi
Keyword(s):  
Nanorod Arrays ◽  
Ni Foam ◽  
Facile Synthesis ◽  
Array Structure ◽  
Rod Array

The hierarchical rod-array structure Mo and Co-based oxidized/phosphides electroplated with FeOOH (NF@P-S450@FeOOH) composites on Ni foam (NF) was prepared using facile hydrothermal and electrodeposition methods. The as-synthesized rod-arrays exhibit excellent...

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