Investigation of IG-SCC growth kinetics in Al-Mg alloys in thin film environments

CORROSION ◽  
10.5006/3833 ◽  
2021 ◽  
Author(s):  
Patrick Steiner ◽  
Zachary Harris ◽  
Carolina Vicente Moraes ◽  
Robert Kelly ◽  
james burns
Keyword(s):  
Thin Film ◽  
Fracture Mechanics ◽  
Crack Growth ◽  
Growth Kinetics ◽  
Computational Modelling ◽  
Close Correlation ◽  
Open Circuit ◽  
Cathodic Current ◽  
Anodized Aluminum ◽  
Intergranular Stress Corrosion

The effect of thin film environments on the intergranular stress corrosion cracking (IG-SCC) behavior of AA5083-H131 was investigated using fracture mechanics-based testing, high-fidelity monitoring of crack growth, and electrochemical potential measurements. A protocol for conducting thin film IG-SCC fracture mechanics experiments with anodized aluminum oxide (AAO) membranes is developed and the ability to maintain films of specific thicknesses without impeding oxygen diffusion during testing is validated via EIS testing and computational modelling. The IG-SCC susceptibility was found to increase once a critical thin film thickness of 82 µm was achieved; above this thickness a duality in IG-SCC susceptibility behavior was observed. These results are analyzed in the context of a coupled anodic dissolution and hydrogen (H) embrittlement mechanism, where susceptibility is found to scale with the cathodic limitation of the governing IG-SCC mechanism. Specifically, thinner film thicknesses led to limitations on the amount of cathodic current availability, which caused a decrease in the dissolution at the crack tip, a less aggressive crack chemistry development, and thus lower levels of H production. A close correlation between the open circuit potential of the bulk surface and the crack growth kinetics was also observed, consistent with trends reported in previous IG-SCC studies on this alloy.

Mechanistic Studies of Intergranular Stress Corrosion Cracking in Al-Mg Alloys under Atmospheric Exposure Conditions

CORROSION ◽  
10.5006/2853 ◽  
2018 ◽  
Vol 74 (10) ◽  
pp. 1117-1131 ◽  
Author(s):  
P.J. Steiner ◽  
J.T. Burns
Keyword(s):  
Stress Corrosion ◽  
Crack Growth ◽  
Growth Kinetics ◽  
Stress Corrosion Cracking ◽  
Close Correlation ◽  
Open Circuit ◽  
Corrosion Cracking ◽  
Intergranular Stress Corrosion ◽  
Chemistry Development ◽  
Intergranular Stress Corrosion Cracking

The effect of atmospheric environments on the intergranular stress corrosion cracking (IG-SCC) behavior of AA5083-H131 and AA5456-H116 was investigated using fracture mechanics-based testing, high-fidelity monitoring of crack growth kinetics, and electrochemical potential measurements. The IG-SCC susceptibility was found to decrease in atmospheric environments as compared to full immersion at −0.8 VSCE. Critically, the decrease in IG-SCC susceptibility was most prevalent for higher levels of sensitization and the more susceptible AA5083-H131 alloy. These results are analyzed in the context of a coupled anodic dissolution and H-embrittlement mechanism, wherein the reduction in IG-SCC susceptibility in the atmospheric environments results from cathodic limitation of the governing IG-SCC mechanism, leading to a decrease in the dissolution at the crack tip, a less aggressive crack chemistry development, and thus lower levels of H production. A close correlation between the open circuit potential of the bulk surface and the crack growth kinetics was observed for environments without a set potential, and correlates well with known potential-dependent IG-SCC observations.

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

Fracture mechanics in design and service: ‘living with defects’ - Application of fracture mechanics to rubber articles, including tyres

1981 ◽  
Vol 299 (1446) ◽  
pp. 189-202 ◽  
Keyword(s):  
Fracture Mechanics ◽  
Crack Growth ◽  
Strain Energy ◽  
Tensile Failure ◽  
Practical Application ◽  
Complicated Fracture ◽  
Fracture Work

The use of a fracture mechanics approach, based on the rate of release of strain energy, to account for various features of the failure of vulcanized rubbers is outlined. The properties considered include those to which fracture mechanics is often applied — tear, tensile failure, crack growth and fatigue — and others to which its application is less usual — abrasion, ozone attack and cutting by sharp objects. The relation of macroscopically observed properties to the basic molecular strength of the material is also discussed. An example of a quantitative practical application of the rubber fracture work, to groove cracking in tyres, is then considered. Finally, the rather more complicated fracture that can occur in rubber—cord laminates is discussed and it is shown that the energetics approach can be applied to some features, at least, of this.

Experimental Study on the Failure Criterion for Brittle Materials in Compression

2011 ◽  
Vol 320 ◽  
pp. 259-262
Author(s):  
Xu Ran ◽  
Zhe Ming Zhu ◽  
Hao Tang
Keyword(s):  
Thin Film ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fracture Mechanics ◽  
Failure Criterion ◽  
Brittle Materials ◽  
Experimental Results ◽  
Experiment Study ◽  
Confining Stress ◽  
Theoretical Results

The mechanical behavior of multi-cracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, based on the previous theoretical results of the failure criterion for brittle materials under compression, experiment study is implemented. The specimens are square plates and are made of cement, sand and water, and the cracks are made by using a very thin film (0.1 mm). The relations of material compressive strength versus crack spacing and the lateral confining stress are obtained from experimental results. The experimental results agree well with the failure criterion for brittle materials under compression, which indicates that the criterion is effective and applicable.

Effective Modeling of Fatigue Crack Growth in Pipelines

2012 ◽  
Author(s):  
Steven J. Polasik ◽  
Carl E. Jaske
Keyword(s):  
Fatigue Crack ◽  
Stress Intensity ◽  
Fatigue Crack Growth ◽  
Fracture Mechanics ◽  
Crack Growth ◽  
Growth Models ◽  
Critical Parameters ◽  
Operating Pressure ◽  
Mechanics Model ◽  
Key Variables

Pipeline operators must rely on fatigue crack growth models to evaluate the effects of operating pressure acting on flaws within the longitudinal seam to set re-assessment intervals. In most cases, many of the critical parameters in these models are unknown and must be assumed. As such, estimated remaining lives can be overly conservative, potentially leading to unrealistic and short reassessment intervals. This paper describes the fatigue crack growth methodology utilized by Det Norske Veritas (USA), Inc. (DNV), which is based on established fracture mechanics principles. DNV uses the fracture mechanics model in CorLAS™ to calculate stress intensity factors using the elastic portion of the J-integral for either an elliptically or rectangularly shaped surface crack profile. Various correction factors are used to account for key variables, such as strain hardening rate and bulging. The validity of the stress intensity factor calculations utilized and the effect of modifying some key parameters are discussed and demonstrated against available data from the published literature.

scholarly journals Dye-Sensitized Nanocrystalline ZnO Solar Cells Based on Ruthenium(II) Phendione Complexes

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Hashem Shahroosvand ◽  
Parisa Abbasi ◽  
Mohsen Ameri ◽  
Mohammad Reza Riahi Dehkordi
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Conversion Efficiency ◽  
Short Circuit ◽  
Photocurrent Density ◽  
Open Circuit ◽  
Zno Thin Film ◽  
Photovoltaic Properties ◽  
Dye Sensitized ◽  
Ft Ir

The metal complexes ( (phen)2(phendione))(PF6)2(1), [ (phen)(bpy)(phendione))(PF6)2(2), and ( (bpy)2(phendione))(PF6)2(3) (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine and phendione = 1,10-phenanthroline-5,6-dione) have been synthesized as photo sensitizers for ZnO semiconductor in solar cells. FT-IR and absorption spectra showed the favorable interfacial binding between the dye-molecules and ZnO surface. The surface analysis and size of adsorbed dye on nanostructure ZnO were further examined with AFM and SEM. The AFM images clearly show both, the outgrowth of the complexes which are adsorbed on ZnO thin film and the depression of ZnO thin film. We have studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phendione complexes, which gave power conversion efficiency of (η) of 1.54% under the standard AM 1.5 irradiation (100 mW cm−2) with a short-circuit photocurrent density () of 3.42 mA cm−2, an open-circuit photovoltage () of 0.622 V, and a fill factor (ff) of 0.72. Monochromatic incident photon to current conversion efficiency was 38% at 485 nm.

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