Low-cycle fatigue behavior and corrosion mechanism of pre-corroded 2A70-T6 aluminum alloy

2020 ◽  
Vol 67 (2) ◽  
pp. 228-239
Author(s):  
Hui Li ◽  
Lei Fu ◽  
Li Lin ◽  
Yu Chen ◽  
YunRong Luo ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Atmospheric Corrosion ◽  
Fatigue Behavior ◽  
Fatigue Performance ◽  
Corrosion Mechanism ◽  
Accelerated Corrosion ◽  
Corrosion Failure ◽  
Content Type ◽  
X Ray

Purpose In summary, it can be found that the current research on the simulation of natural atmospheric dry–wet alternating accelerated corrosion mainly focused on the study of electrochemical corrosion process and the study of corrosion rate; the micro-pre-corrosion mechanism of materials in this environment, especially for materials. The specific effects of fatigue and fracture performance still lack detailed research. Accordingly, this study aims to more realistically simulate the effect of natural atmospheric corrosion environment on the corrosion resistance and fatigue performance of aircraft skin. Design/methodology/approach In this study, the uniaxial strain control method was used to test the fatigue performance of pre-corrosion samples under simulated natural atmospheric corrosion using MTS809 tensile-torque composite fatigue machine. Scanning electron microscopy, X-ray energy spectrum analysis, atomic force microscopy and X-ray diffraction analysis were used. Fatigue fracture, corrosion morphology and corrosion products were analyzed. Findings The results show that the deep corrosion pit caused by pre-corrosion environment leads to multi-source initiation of crack; the fatigue life of pre-corroded sample decreases by about one-half, chloride ion invades the material and promotes intergranular corrosion; life prediction results show that the natural atmospheric corrosive environment mainly affects the plastic term in the Manson–Coffin formula resulting in a decrease in fatigue life. Originality/value Innovative experimental schemes and materials are used and the test temperature and relative humidity are strictly controlled. The corrosion failure mechanism of 2A70-T6 aluminum alloy under alternating wet and dry accelerated corrosion environment and its influence on fatigue behavior were obtained.

Corrosion mechanism and fatigue behavior of 2A70-T6 aluminum alloy under alternating corrosion and fatigue

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lei Fu ◽  
Hui Li ◽  
Li Lin ◽  
Qingyuan Wang ◽  
Qi Fan ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Corrosion Fatigue ◽  
Intergranular Corrosion ◽  
Fatigue Behavior ◽  
Cumulative Damage ◽  
Corrosion Mechanism ◽  
Corrosive Environment ◽  
Content Type ◽  
Damage Rule

Purpose Most supersonic aircraft were manufactured using 2A70 aluminum alloy. The purpose of this paper is to study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. Design/methodology/approach For this purpose, the aluminum alloy samples were subjected to pre-corrosion and alternating corrosion-fatigue experiments. The failure mechanisms of corrosion and corrosion fatigue were analyzed using microscopic characterization methods of electrochemical testing, X-ray diffraction and scanning electron microscopy. Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life. Findings The results showed that the corrosion damage caused by the corrosive environment was gradually connected by pitting pits to form denudation pits along grain boundaries. The deep excavation of chloride ions and the presence of intergranular copper-rich phases result in severe intergranular corrosion morphology. During cyclic loading, alternating hardening and softening occurred. The stress concentration caused by surface pitting pits and denudation pits initiated fatigue cracks at intergranular corrosion products. At the same time, the initiation of multiple fatigue crack sources was caused by the corrosion environment and the morphology of the transient fracture zone was also changed, but the crack propagation rate was not basically affected. The polarization curve and impedance analysis results showed that the corrosion rate increases first, decreases and then increases. Fatigue failure behavior was directly related to micro characteristics such as corrosion pits and microcracks. Originality/value In this research, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. To study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, the Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life.

Effects of Ultrasonic Deep Rolling on Fatigue Performance of Pre-Corroded 7A52 Aluminum Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 897-900 ◽  
Author(s):  
Xiong Lin Ye ◽  
You Li Zhu ◽  
Dong Hu Zhang
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Aluminum Alloys ◽  
Residual Stresses ◽  
Fatigue Behavior ◽  
Fatigue Performance ◽  
Deep Rolling ◽  
Fatigue Crack Nucleation ◽  
7A52 Aluminum Alloy ◽  
Compressive Residual Stresses

The effects of ultrasonic deep rolling (UDR) on the fatigue behavior of pre-corroded 7A52 aluminum alloys were investigated. By means of X-Ray diffraction stress measurements and scanning electron microscopy (SEM), residual stress and fractograph of 7A52 aluminum alloys with and without UDR treatment were analyzed. The results indicated that the UDR produced compressive residual stresses with depth approaching 1mm. UDR treatment can extend the fatigue life of the pre-corroded 7A52 specimens to a large extent, depending on the level of corrosion and UDR parameter. For the slightly corrode specimens, the UDR treatment changed the fatigue crack nucleation site from surface to the transition zone between the compressive residual stresses and tensile stresses, resulted in a much longer fatigue life. For the severely corrode specimens, the crack still nucleated by intergranular cracking, however, due to the compressive residual stresses introduced and the closure of the corrosion pits and corrosion micro-crocks, UDR treatment still improved fatigue performance of the pre-corroded 7A52 aluminum alloy substantially.

Tensile and fatigue behavior of layered acrylonitrile butadiene styrene

2015 ◽  
Vol 21 (3) ◽  
pp. 270-278 ◽  
Author(s):  
Sophia Ziemian ◽  
Maryvivian Okwara ◽  
Constance Wilkens Ziemian
Keyword(s):  
Fatigue Life ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Acrylonitrile Butadiene Styrene ◽  
Fatigue Performance ◽  
Experimental Investigations ◽  
Content Type ◽  
Astm Standard ◽  
Fused Deposition ◽  
Butadiene Styrene

Purpose – This paper aims to define the effect of specimen mesostructure on the monotonic tensile behavior and tensile-fatigue life of layered acrylonitrile butadiene styrene (ABS) components fabricated by fused deposition modeling (FDM). Design/methodology/approach – Tensile tests were performed on FDM dogbone specimens with four different raster orientations according to ASTM standard D638-03. Resulting ultimate tensile stresses (UTS) for each raster orientation were used to compute the maximum stress for fatigue testing, i.e. 90, 75, 60 and 50 or 45 per cent nominal values of the UTS. Multiple specimens were subjected to tension – tension fatigue cycling with stress ratio of R = 0.10 in accordance with ASTM standard D7791-12. Findings – Both tensile strength and fatigue performance exhibited anisotropic behavior. The longitudinal (0°) and default (+45/−45°) raster orientations performed significantly better than the diagonal (45°) or transverse (90°) orientations in regards to fatigue life, as displayed in the resulting Wohler curves. Practical implications – Raster orientation has a significant effect on the fatigue performance of FDM ABS components. Aligning FDM fibers along the axis of the applied stress provides improved fatigue life. If the direction of applied stresses is not expected to be constant in given application, the default raster orientation is recommended. Originality/value – This project provides knowledge to the limited work published on the fatigue performance of FDM ABS components. It provides S-N fatigue life results that can serve as a foundation for future work, combining experimental investigations with theoretical principles and the statistical analysis of data.

Corrosion of a chrome-moly pipe transporting sulfuric acid in a demineralization section: a failure analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Andres Marquez ◽  
Chris Maharaj
Keyword(s):  
Sulfuric Acid ◽  
Material Selection ◽  
Real Life ◽  
Main Idea ◽  
Petrochemical Plant ◽  
Material Loss ◽  
Corrosion Failure ◽  
Content Type ◽  
Characterization Methods ◽  
X Ray

Purpose The purpose of this study was to carry out an analysis of the corrosion failure on a chrome-moly pipeline transporting highly concentrated sulfuric acid in a demineralization section at a petrochemical plant, along with the feasibility of using inhibitors to minimize the corrosive effects of sulfuric acid. Design/methodology/approach X-ray fluorescence spectroscopy, high-resolution optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and accelerated corrosion experiments (ACE) were performed. Findings Erosion-corrosion failure was confirmed by the significant reduction in thickness of the internal surface of the material exposed to sulfuric acid, as well as the formation of an oxide scale/layer. ACE accurately predicted high material loss from exposure to sulfuric acid. Moreover, adding ascorbic acid as a corrosion inhibitor (even at low concentrations) was found to reduce the oxidation by more than 50% in the presence of sulfuric acid. Originality/value The main idea/purpose of this work relies on the analysis of recurrent real-life corrosion-attributed failures that are common in industry but are not properly addressed for a variety of reasons, poor management and lack of corrosion preventive strategies being the main ones. This study once again highlights readily available solutions/implementations that are capable of not only addressing technically the issue investigated but also, and as important, economically. By using microscopic imaging, reliable well-tested and widely used characterization methods, all combined with basic experiments and tests, the nature of the repetitive failure investigated was clearly demonstrated as well as readily available alternatives to minimize it in the short term. Nevertheless, implementing material selection techniques appropriately as effective corrosion prevention/control and cost-saving strategies must be enforced in any process.

scholarly journals Effects of Actual Marine Atmospheric Pre-Corrosion and Pre-Fatigue on the Fatigue Property of 7085 Aluminum Alloy

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 81
Author(s):  
Laixin Shi ◽  
Lin Xiang ◽  
Jianquan Tao ◽  
Jun Liu ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Pitting Corrosion ◽  
Atmospheric Corrosion ◽  
Fatigue Property ◽  
Outdoor Exposure ◽  
Fatigue Tests ◽  
Constant Amplitude ◽  
Fatigue Fractography ◽  
Corrosion Mode

Effects of actual marine atmospheric precorrosion and prefatigue on the fatigue property of 7085-T7452 aluminum alloy were investigated by using the methods of marine atmospheric outdoor exposure tests and constant amplitude axial fatigue tests. Marine atmospheric corrosion morphologies, fatigue life, and fatigue fractography were analyzed. After three months of outdoor exposure, both pitting corrosion and intergranular corrosion (IGC) occurred, while the latter was the dominant marine atmospheric corrosion mode. Marine atmospheric precorrosion could result in a dramatical decrease in the fatigue life of the as-received 7085-T7452 aluminum alloy, while selective prefatigue can improve the total fatigue life of the precorroded specimen. The mechanism of the actual marine atmospheric corrosion and its effects on the fatigue life of the 7085-T7452 aluminum alloy were also discussed.

Optimization of internal thread structure of force sensor considering fatigue performance

Sensor Review ◽  
2019 ◽  
Vol 39 (6) ◽  
pp. 835-843
Author(s):  
Hongchun Sun ◽  
Tianlu Wang ◽  
Xindong Zhang
Keyword(s):  
Fatigue Life ◽  
Force Sensor ◽  
Fatigue Performance ◽  
Internal Thread ◽  
Outer Diameter ◽  
Optimized Design ◽  
Content Type ◽  
Performance Requirements ◽  
Design Requirements ◽  
Thread Structure

Purpose Fatigue damage of internal threads has gradually become the main failure mode of force sensor. To make the internal thread structure of force sensor meet the fatigue performance requirements, the design criteria of static strength and fatigue life are comprehensively considered in this paper. Design/methodology/approach The variation of static stress and fatigue life with the size of the main structure is obtained by simulation. By changing the number of thread turns, the hub height and outer diameter of the hub, the optimized design of the spoke force sensor is determined. Findings The experiment was carried out based on the determined optimized structure, and the results showed that the fatigue life meets the design requirements. Originality/value This research has certain guiding significance for the design and developments of high-cycle fatigue force sensors.

scholarly journals Multiaxial fatigue behavior of 2618 aluminum alloy

2019 ◽  
Vol 300 ◽  
pp. 09003
Author(s):  
Benaïssa Malek ◽  
Catherine Mabru ◽  
Michel Chaussumier
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Internal Pressure ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Mean Stress ◽  
Research Project ◽  
Pressure Tests

The purpose of the present research project is to study multiaxial fatigue behavior of 2618 alloy. The influence of mean stress on the fatigue behavior under tension and torsion is particularly investigated. Fatigue tests under combined tensile-torsion, in or out of phase, as well as combined tensile-torsion-internal pressure tests have also been conducted. Multiaxial fatigue results are analyzed according to Fatemi-Socie criterion to predict the fatigue life.

Long-term monitoring of zinc corrosion behavior in typical hot and dry atmosphere environment in Turpan, China

2018 ◽  
Vol 65 (5) ◽  
pp. 471-483 ◽  
Author(s):  
Chunhui Kang ◽  
Decheng Kong ◽  
JiZheng Yao ◽  
Chunyun Guo ◽  
Li Wang ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Exposure Time ◽  
Corrosion Products ◽  
Corrosion Mechanism ◽  
Corrosion Morphology ◽  
Transfer Resistance ◽  
Positive Direction ◽  
Pure Zinc ◽  
Content Type ◽  
X Ray

Purpose This paper aims to investigate the corrosion behavior of zinc in a typical hot and dry atmosphere. It proposes the dynamic corrosion for different exposure periods. Results can provide the basic data and corrosion mechanism of zinc in such environment. Design/methodology/approach In this paper, the authors investigated the corrosion behavior of pure zinc exposed in the typical hot and dry environment in Turpan for one-four years, which has never been studied. Scanning electron microscopy, laser scanning confocal microscopy, electron probe micro-analyzer (EPMA), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were conducted to measure the corrosion morphology and products of zinc. Finally, combining electrochemical impedance spectroscopy and scanning Kelvin probe techniques, the corrosion mechanism of zinc in Turpan was examined. Findings The thickness loss of the zinc followed an exponential law with respect to exposure time: D = 3.17 t0.61, and both of the rust layer resistance and the charge transfer resistance increased with exposure time. The corrosion products mainly comprised ZnO, Zn(OH)2, Zn5(CO3)2(OH)6, Zn4SO4(OH)6·5H2O and Zn12(SO4)3Cl3(OH)15·5H2O. The Kelvin potentials shifted toward the positive direction from −0.380 to −0.262 V (vs saturated calomel electrode [SCE]) when the exposure time extended from one to four years and the distribution of the corrosion products became more and more uniform. Originality/value The corrosion behavior of pure zinc in the typical hot and dry environment in Turpan has not been studied. The dynamic corrosion for different exposure periods was obtained. The corrosion products were systemically investigated via energy-dispersive X-ray spectroscopy, EPMA, XPS and XRD.

Investigation on fatigue behavior of single SnAgCu/SnPb solder joint by rapid thermal cycling

2015 ◽  
Vol 27 (2) ◽  
pp. 76-83 ◽  
Author(s):  
Jibing Chen ◽  
Yanfang Yin ◽  
Jianping Ye ◽  
Yiping Wu
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Solder Bump ◽  
Fatigue Behavior ◽  
Interfacial Microstructure ◽  
Content Type ◽  
X Ray ◽  
Snpb Solder ◽  
Rapid Thermal Cycling

Purpose – The purpose of this paper is to investigate the thermal fatigue behavior of a single Sn-3.0Ag-0.5Cu (SAC) lead-free and 63Sn-37Pb (SnPb) solder joint treated by rapidly alternating heating and cooling cycles. Design/methodology/approach – With the application of electromagnetic-induced heating, the specimen was heated and cooled, controlled with a system that uses a fuzzy logic algorithm. The microstructure and morphology of the interface between the solder ball and Cu substrate was observed using scanning electron microscopy. The intermetallic compounds and the solder bump surface were analyzed by energy-dispersive X-ray spectroscopy and X-ray diffraction, respectively. Findings – The experimental results showed that rapid thermal cycling had an evident influence on the surface and interfacial microstructure of a single solder joint. The experiment revealed that microcracks originate and propagate on the superficial oxide of the solder bump after rapid thermal cycling. Originality/value – Analysis, based on finite element modeling and metal thermal fatigue mechanism, determined that the rimous cracks can be explained by the heat deformation theory and the function of temperature distribution in materials physics.

Synergistic effect of chloride and NO2 on the atmospheric corrosion of bronze

2009 ◽  
Vol 56 (6) ◽  
pp. 299-305 ◽  
Author(s):  
Xia Cao ◽  
Ning Wang ◽  
Ning Liu
Keyword(s):  
Synergistic Effect ◽  
Design Methodology ◽  
Atmospheric Corrosion ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Impedance Measurements ◽  
Content Type ◽  
X Ray ◽  
Corrosion Kinetics ◽  
Tension Tests

PurposeThe purpose of this paper is to investigate the effect of chloride along with NO2 on the atmospheric corrosion of bronze using exposure tests.Design/methodology/approachSurface tension tests and electrochemical impedance measurements together with scanning electron microscopy (SEM) with energy dispersive atomic X‐ray, and X‐ray diffraction are used to characterize the corrosion behavior.FindingsThe results of the weight loss measurements show that the whole corrosion kinetics can be described approximately by: ΔW=atb; the synergistic effect of chloride and NO2 is observed clearly, though no nitrate existed in the corrosion products.Originality/valueA new catalyst theory has been suggested in this paper, i.e. that NO2 acts as a catalyst during the corrosion process when significant quantities of chloride also are present.

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