Temperature and Orientation Dependence of Surface Film Effects in Single Crystal Nial

1986 ◽  
Vol 81 ◽  
Author(s):  
R.D. Noebe ◽  
J.T. Kim ◽  
R. Gibala
Keyword(s):  
Single Crystal ◽  
Crystallographic Orientation ◽  
Surface Film ◽  
Orientation Dependence ◽  
Surface Films ◽  
Temperature Dependent ◽  
Paper Surface ◽  
Bcc Metals ◽  
Coated Materials ◽  
Ordered Alloys

AbstractDuring deformation of bcc metals and bcc-based ordered alloys, conditions of elastic and plastic constraint associated with the presence of thin adherent surface films can be responsible for introducing increased densities of mobile dislocations in the metal, resulting in enhanced ductility and reduced yield and flow stresses of the film-coated materials. In the present paper, surface film effects were investigated as a function of temperature and crystallographic orientation for single crystal β-NiAl. Appreciable temperature-dependent and orientation-dependent surface film effects were observed, as were significant effects of film adherence on the observation of surface film softening.

Reaction of nitrobenzene on gold single-crystal electrodes: surface crystallographic orientation dependence

1999 ◽  
Vol 477 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Liang-Jen Fan ◽  
Chi Wang ◽  
Si-Chung Chang ◽  
Yaw-wen Yang
Keyword(s):  
Single Crystal ◽  
Crystallographic Orientation ◽  
Orientation Dependence

The Effect of Surface Oxide Films on the Mechanical Behavior of NiAl

1984 ◽  
Vol 39 ◽  
Author(s):  
R. D. Noebe ◽  
R. Gibala
Keyword(s):  
Mechanical Behavior ◽  
Surface Film ◽  
Dislocation Core ◽  
The Body ◽  
Surface Films ◽  
Intermetallic Alloys ◽  
Body Centered Cubic ◽  
Cubic Metals ◽  
Bcc Metals ◽  
Ordered Intermetallic

ABSTRACTThin surface films have been shown to enhance the ductility and decrease the flow stress of several body-centered cubic metals at temperatures T < 0.2 Tm. The origin of this effect lies in the large difference in the intrinsic mobilities of edge and screw dislocations in body-centered cubic crystals. B2 ordered intermetallic alloys, although simple cubic in structure, are based on the body-centered cubic structure and have dislocation core structures, dislocation mobilities and temperature and orientation dependent deformation qualitatively similar to that of bcc metals. This investigation was initiated to examine possible effects of surface films on the mechanical behavior of B2 ordered intermetallic alloys, using oxidized NiAl as the initial material for investigation. Experiments were performed on an impure non-stoichiometric (47.1 at.% Al) single crystal material with an axial orientation near [123]. Surface film softening was observed at room temperature in compression at a strain rate of 2 x 10-4 s-1. Flow stresses of the oxide coated crystals were as much as 20% lower than those of identically prepared uncoated crystals. The strains to fracture of coated specimens were larger than those of uncoated specimens and in a few instances the ductility enhancement was as much as four times. Of the several oxides examined, the largest softening effects were found for a thermally deposited delta-A1203 film formed at 1000 °C for 1 hour. The current results for NiAl are compared to results previously obtained for bcc metals. Experiments which could further enhance the film softening effects observed in B2 ordered intermetallic alloys are suggested.

Surface Films on Zircaloy-2 Samples Cracked in Neutral Aqueous NaCl by Stress Corrosion

1973 ◽  
Vol 31 ◽  
pp. 46-47
Author(s):  
R.A. Ploc
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Film Thickness ◽  
Stress Corrosion ◽  
Zirconium Dioxide ◽  
Surface Film ◽  
Surface Films ◽  
Continuous Layer ◽  
Transmission Electron ◽  
Product Film

Samples of low-nickel Zircaloy-2 (material MLI-788-see(1)), when anodically polarized in neutral 5 wt% NaCl solutions, were found to be susceptible to pitting and stress corrosion cracking. The SEM revealed that pitting of stressed samples was occurring below a 2000Å thick surface film which behaved differently from normal zirconium dioxide in that it did not display interference colours. Since the initial film thickness was approximately 65Å, attempts were made to examine the product film by transmission electron microscopy to deduce composition and how the corrosion environment could penetrate the continuous layer.

Crystallographic orientation dependence of Charpy impact behaviours in stainless steel 316L fabricated by laser powder bed fusion

2021 ◽  
pp. 102104
Author(s):  
Xianglong Wang ◽  
Oscar Sanchez-Mata ◽  
Sıla Ece Atabay ◽  
Jose Alberto Muñiz-Lerma ◽  
Mohammad Attarian Shandiz ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Crystallographic Orientation ◽  
Charpy Impact ◽  
Orientation Dependence ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Stainless Steel 316L ◽  
Powder Bed

scholarly journals Crystallographic Orientation Dependence of Surface Segregation and Alloying on PdCu Catalysts for CO2 Hydrogenation

2021 ◽  
Vol 12 (10) ◽  
pp. 2570-2575
Author(s):  
Lukas Pielsticker ◽  
Ioannis Zegkinoglou ◽  
Zhong-Kang Han ◽  
Juan J. Navarro ◽  
Sebastian Kunze ◽  
...  
Keyword(s):  
Crystallographic Orientation ◽  
Surface Segregation ◽  
Orientation Dependence ◽  
Co2 Hydrogenation
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