Corrosion damage evolution of the aircraft aluminum alloy 2024 T3

2016 ◽  
Vol 7 (1) ◽  
pp. 25-46 ◽  
Author(s):  
Spiros Pantelakis ◽  
Dorothea Setsika ◽  
Apostolos Chamos ◽  
Anna Zervaki
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Damage Evolution ◽  
Structural Integrity ◽  
Corrosion Damage ◽  
Tensile Tests ◽  
Content Type ◽  
Experimental Database ◽  
Aluminum Alloy 2024 ◽  
The Impact

Purpose – The purpose of this paper is to quantify the corrosion damage evolution that has occurred on the aircraft aluminum alloy 2024 after the exposure to Exfoliation Corrosion Test (EXCO) solution. Moreover, the effect of the evolving corrosion damage on the materials mechanical properties has been assessed. The relevance of the corrosion damage induced by the exposure to the laboratory EXCO for linking it to the damage developed after the exposure of the material on several outdoor corrosive environments or in service is discussed. Design/methodology/approach – To induce corrosion damage the EXCO has been used. For the quantification of corrosion damage the metallographic features considered have been pit depth, diameter, pitting density and pit shape. The effect of the evolving corrosion damage on the materials mechanical properties has been assessed by means of tensile tests on pre corroded specimens. Findings – The results have shown that corrosion damage starts from pitting and evolves to exfoliation, after the development of intergranular corrosion. This evolution is expressed by the increase of the depth of attack, as well as through the significant growth of the diameter of the damaged areas. The results of the tensile tests performed on pre corroded material made an appreciable decrease of the materials tensile properties evident. The decrease of the tensile ductility may become dramatic and increases on severity with increasing corrosion exposure time. SEM fractography revealed a quasi-cleavage zone beneath the depth of corrosion attack. Originality/value – The results underline the impact of corrosion damage on the mechanical behavior of the aluminum alloy 2024 T3 and demonstrate the need for further investigation of the corrosion effect on the structural integrity of the material. This work provides an experimental database concerning the quantification of corrosion damage evolution and the loss of material properties due to corrosion.

Structural Modifications of the Aluminium Alloy in Conditions of Additional Shock Impulse Load

2013 ◽  
Vol 592-593 ◽  
pp. 598-601 ◽  
Author(s):  
Volodymyr Hutsaylyuk ◽  
Mykola Czausow ◽  
Lucjan Śnieżek ◽  
Andrii Pylypenko ◽  
Tomasz Ślęzak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Room Temperature ◽  
Structural Changes ◽  
Physical Nature ◽  
Structural Modifications ◽  
Equilibrium Processes ◽  
Impulse Load ◽  
Aluminum Alloy 2024 ◽  
The Impact

This work has been done to research the physical nature of the mechanism of structural changes of the aluminum alloy 2024-T3 at the conditions of additional impulse load. There was revealed an anomaly growth in plasticity of the material after such type load realization at the room temperature. Based on fractographical research the impact of dynamic non-equilibrium processes on the structural changes of the material and its macro-mechanical properties was analyzed.

Numerical simulation of tensile behavior of corroded aluminum alloy 2024 T3

2015 ◽  
Vol 6 (4) ◽  
pp. 451-467 ◽  
Author(s):  
Dorothea Setsika ◽  
Konstantinos Tserpes ◽  
Spiros Pantelakis
Keyword(s):  
Aluminum Alloy ◽  
Mechanical Behavior ◽  
Corrosion Damage ◽  
Exposure Period ◽  
Tensile Specimen ◽  
Tensile Behavior ◽  
Content Type ◽  
Structural Part ◽  
Representative Unit Cell ◽  
Aluminum Alloy 2024

Purpose – The purpose of this paper is to develop a multi-scale modeling approach for simulating the tensile behavior of corroded aluminum alloy 2024 T3. Design/methodology/approach – The approach combines two FE models: a model of a three-dimensional representative unit cell representing a pit and a model of the tensile specimen. The models lie at the micro- and macro-scales, respectively. The local homogenized mechanical behavior of the corroded material is simulated for different pit configurations. Then, the behavior of the pits is introduced into different areas (elements) of the tensile specimen and final analyses are performed to simulate the mechanical behavior of the corroded material. The approach has been applied to six different exposure periods of the exfoliation corrosion test. Findings – The numerical results show that the presence of pits and exfoliated areas reduces the yield strength of the material. The comparison of predicted elongation to fracture with the experimental of each exposure period value allows for the indirect assessment of the effect of hydrogen embrittlement. Originality/value – Since the characteristics of corrosion damage evolution with exposure time are constant for the specific material, the model could be applied for the simulation of the mechanical behavior of any corroded structural part (e.g. a mechanically fastened panel) made from the aluminum 2024 T3 alloy.

scholarly journals Ex Vivo Dermis Mechanical Behavior in Relation to Decellularization Treatment Length

2016 ◽  
Vol 10 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Mara Terzini ◽  
Cristina Bignardi ◽  
Carlotta Castagnoli ◽  
Irene Cambieri ◽  
Elisabetta M. Zanetti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Sodium Hydroxide ◽  
Structural Properties ◽  
Structural Integrity ◽  
Ex Vivo ◽  
Tensile Tests ◽  
Treatment Length ◽  
Native Tissue ◽  
The Impact

Background: The dermis is a commonly used source tissue for biologic scaffolds; all cellular and nuclear materials need to be removed to limit the inflammatory immune response by the host organism. The decellularization is critical because it must preserve the structural integrity of the extracellular matrix. This work has analyzed a decellularization procedure commonly followed for the dermal tissue that is a chemical treatment with sodium hydroxide. The goal of this work is to identify the optimal treatment length on the basis of structural properties. Methods: Tensile tests have been performed on the native tissue and on tissues decellularized for 1-7 weeks in sodium hydroxide. The collected data have been analyzed through Tukey-Kramer test to assess if the mechanical properties (ultimate tensile stress and elastic modulus) of decellularized tissues were significantly different from the properties of the native tissue. These tests have been performed on specimens cut along two orthogonal directions (parallel and perpendicular to Langer’s lines). Results: The decellularization treatment performed with sodium hydroxide in general weakens the tissue: both the ultimate stress and the elastic modulus get lower. The structural properties along Langer lines orientation are more strongly impacted, while the structural properties orthogonal to Langer lines can be preserved with an optimal duration of the decellularization treatment that is 5-6 weeks. Conclusion: The duration of the decellularization treatment is critical not only to reach a complete decellularization, but also to preserve the mechanical properties of the tissue; 5-6 week treatment performed with sodium hydroxide allows preserving the mechanical properties of the native tissue perpendicularly to Langer lines orientation, and minimizing the impact of the decellularization process on the mechanical properties along the Langer lines orientation.

scholarly journals Microstructure and Texture Evolution with Relation to Mechanical Properties of Compared Symmetrically and Asymmetrically Cold Rolled Aluminum Alloy

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 156 ◽  
Author(s):  
Jakob Kraner ◽  
Peter Fajfar ◽  
Heinz Palkowski ◽  
Goran Kugler ◽  
Matjaž Godec ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
Strain Ratio ◽  
Tensile Tests ◽  
Asymmetric Rolling ◽  
Plastic Strain Ratio ◽  
Rolled Aluminum ◽  
The Impact

The impact of asymmetric cold rolling was quantitatively assessed for an industrial aluminum alloy AA 5454. The asymmetric rolling resulted in lower rolling forces and higher strains compared to conventional symmetric rolling. In order to demonstrate the positive effect on the mechanical properties with asymmetric rolling, tensile tests, plastic-strain-ratio tests and hardness measurements were conducted. The improvements to the microstructure and the texture were observed with a light and scanning electron microscope; the latter making use of electron-backscatter diffraction. The result of the asymmetric rolling was a much lower planar anisotropy and a more homogeneous metal sheet with finer grains after annealing to the soft condition. The increased isotropy of the deformed and annealed aluminum sheet is a product of the texture heterogeneity and reduced volume fractions of separate texture components.

Effect of Artificial Aging on the Mechanical Properties of an Aerospace Aluminum Alloy 2024

2012 ◽  
Vol 326-328 ◽  
pp. 193-198 ◽  
Author(s):  
Danieli A.P. Reis ◽  
Antônio Augusto Couto ◽  
N.I. Domingues Jr. ◽  
Ana Cláudia Hirschmann ◽  
S. Zepka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Aluminum Alloy ◽  
Specific Weight ◽  
Tensile Tests ◽  
Test Machine ◽  
Constant Frequency ◽  
Fracture Surfaces ◽  
Heat Treated ◽  
Aluminum Alloy 2024

Aluminum alloys have low specific weight, relatively high strength and high corrosion resistance and are used in many applications. Aluminum Alloy 2024 is widely used for aircraft fuselage structures, owing to its mechanical properties. In this investigation, Aluminum Alloy 2024 was given solid solution treatments at 495, 505, and 515°C followed by quenching in water. It was then artificially aged at 190 and 208°C. Subsequently, hardness measurements, tensile tests as well as impact and fatigue tests were carried out on the heat treated alloys to determine the mechanical properties. The tensile and hardness tests revealed similar mechanical properties for specimens of this alloy that were given the three solid solution treatments. Aluminum Alloy 2024 specimens that were solid solution treated at 515°C and artificially aged at 208°C for 2h exhibited the highest yield and tensile strength. In general, the increase in strength was accompanied by a decrease in ductility. Cyclic fatigue studies were conducted with symmetric tension-compression stresses at room temperature, using a bending-rotation test machine. The alloy solution heat treated at 515°C and aged at 208°C/2h was fatigue tested at constant frequency. The relation between stress amplitude and cycles to failure was established, enabling the fatigue strength to be predicted at more than 7.8x106cycles, with maximum stress of 110.23 MPa. The fracture surfaces of specimens that failed after fewer cycles showed mainly precipitates and micro voids, whereas specimens that fractured after a higher number of cycles indicated that cracks initiated at the surface. The high cycle fatigue fracture surfaces revealed pores that could be due to precipitates from the matrix.

scholarly journals Process control testing for fused filament fabrication

2017 ◽  
Vol 23 (2) ◽  
pp. 246-256 ◽  
Author(s):  
Stephen Oluwashola Akande ◽  
Kenny Dalgarno ◽  
Javier Munguia
Keyword(s):  
Mechanical Properties ◽  
Impact Test ◽  
Structural Integrity ◽  
Fused Filament Fabrication ◽  
Influence Of Process Parameters ◽  
Content Type ◽  
Machine Performance ◽  
And Control ◽  
The Impact

Purpose The purpose of this research is to determine what tests can be most useful in quality assurance and control when using fused filament fabrication (FFF) 3D printing machines. The quality of the bond between layers is critical for the structural integrity of the fused filament fabricated parts. Design/methodology/approach Therefore, to determine the influence of process parameters on the quality of parts’ tensile, flexural, notched and un-notched impact, test specimens were fabricated in polylactic acid (PLA) using FFF with different layer thicknesses, fill densities, orientation and print speeds. The mechanical properties were then assessed along with the accuracy and mass of the samples. Findings It is concluded that a notched impact test gives a measure of interlayer bond strength which can be used across build styles to track machine performance, and that this, together with the mass and dimensions of the impact-test specimens, offers an appropriate set of tests capable of tracking the mechanical properties of parts produced using the FFF technique. Originality/value Therefore, this research finding will be of value in benchmarking FFF machines for quality parts fabrications.

scholarly journals Strength Enhancement of Superduplex Stainless Steel Using Thermomechanical Processing

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1094
Author(s):  
M. A. Lakhdari ◽  
F. Krajcarz ◽  
J. D. Mithieux ◽  
H. P. Van Landeghem ◽  
M. Veron
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Thermomechanical Processing ◽  
Tensile Tests ◽  
Image Correlation ◽  
Strength Enhancement ◽  
Industrial Material ◽  
Superduplex Stainless Steel ◽  
The Impact ◽  
Strength Improvement

The impact of microstructure evolution on mechanical properties in superduplex stainless steel UNS S32750 (EN 1.4410) was investigated. To this end, different thermomechanical treatments were carried out in order to obtain clearly distinct duplex microstructures. Optical microscopy and scanning electron microscopy, together with texture measurements, were used to characterize the morphology and the preferred orientations of ferrite and austenite in all microstructures. Additionally, the mechanical properties were assessed by tensile tests with digital image correlation. Phase morphology was not found to significantly affect the mechanical properties and neither were phase volume fractions within 13% of the 50/50 ratio. Austenite texture was the same combined Goss/Brass texture regardless of thermomechanical processing, while ferrite texture was mainly described by α-fiber orientations. Ferrite texture and average phase spacing were found to have a notable effect on mechanical properties. One of the original microstructures of superduplex stainless steel obtained here shows a strength improvement by the order of 120 MPa over the industrial material.

scholarly journals Mechanical Properties of Spruce Wood Extracted from GLT Beams Loaded by Fire

2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cross Section ◽  
Negative Impact ◽  
Tensile Tests ◽  
Thermal Recovery ◽  
Bending Test ◽  
Small Scale ◽  
Spruce Wood ◽  
The Impact

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.

scholarly journals Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1242
Author(s):  
Olga Mysiukiewicz ◽  
Paulina Kosmela ◽  
Mateusz Barczewski ◽  
Aleksander Hejna
Keyword(s):  
Mechanical Properties ◽  
Melt Flow Index ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Metal Composites ◽  
Pre Treatment ◽  
The Impact ◽  
Properties Of Composites

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

scholarly journals A DIC-Based Study on Fatigue Damage Evolution in Pre-Corroded Aluminum Alloy 2024-T4

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2243 ◽  
Author(s):  
Haipeng Song ◽  
Changchun Liu ◽  
Hao Zhang ◽  
Sean Leen
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Crack Initiation ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
Image Correlation ◽  
Multiple Cracks ◽  
Mixed Mode Fracture ◽  
Corrosion Condition ◽  
Aluminum Alloy 2024

This paper investigates the fatigue damage and cracking behavior of aluminum alloy 2024-T4 with different levels of prior corrosion. Damage evolution, crack initiation and propagation were experimentally analyzed by digital image correlation, scanning electron microscopy and damage curves. Prior corrosion is shown to cause accelerated damage accumulation, inducing premature fatigue crack initiation, and affecting crack nucleation location, crack orientation and fracture path. For the pre-corrosion condition, although multiple cracks were observed, only one corrosion-initiated primary crack dominates the failure process, in contrast to the plain fatigue cases, where multiple cracks propagated simultaneously leading to final coalescence and fracture. Based on the experimental observations, a mixed-mode fracture model is proposed and shown to successfully predict fatigue crack growth and failure from the single dominant localized corrosion region.

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