SEM In Situ Study on Pre-Corrosion and Fatigue Cracking Behavior of LY12CZ Aluminum Alloy

2012 ◽  
Vol 525-526 ◽  
pp. 81-84 ◽  
Author(s):  
Xu Dong Li ◽  
Zhi Tao Mu ◽  
Zhi Guo Liu
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Fatigue ◽  
Fatigue Cracking ◽  
Corrosion Damage ◽  
Experimental Investigations ◽  
Aircraft Industry ◽  
Cracking Behavior ◽  
Corrosion Pit ◽  
Scanning Electron

Corrosion fatigue is a form of degradation subjected to combined damage of mechanical stress and corrosive medium, which is an issue in aircraft industry. Experimental investigations on prior corrosion fatigue cracking behavior of LY12CZ were conducted with scanning electron microscope (SEM). Results indicate corrosion damage is important for the fatigue small cracking behavior of LY12CZ aluminum alloy. The effect of corrosion pit on fatigue crack can be characterized by the depth of corrosion pit. Based on small crack, another way to evaluate crack growth rate for AALY12CZ is proposed.

SEM In Situ Study on Fatigue Crack Growth of LC9 Aluminum Alloy Subjected to Elevated Temperature

2013 ◽  
Vol 834-836 ◽  
pp. 356-359 ◽  
Author(s):  
Zeng Jie Cai ◽  
Xu Dong Li ◽  
Ming Ming Jia
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Elevated Temperature ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Cracking ◽  
Experimental Investigations ◽  
Cracking Behavior ◽  
Growth Crack

Experimental investigations of fatigue cracking behavior of LC9 aluminum alloy (AA LC9) subjected to elevated temperature were conducted with scanning electron microscope (SEM). Results indicate elevated temperature is important for the fatigue crack growth of AA LC9. Based on small crack growth, crack growth rate for AA LC9 is characterized.

Fatigue Damage Evaluation Research of Aluminum Alloy Based on Energy Degradation

2014 ◽  
Vol 937 ◽  
pp. 150-153
Author(s):  
Xu Dong Li ◽  
Lan Zou ◽  
Zhi Tao Mu ◽  
Guang Ming Kong
Keyword(s):  
Aluminum Alloy ◽  
Elevated Temperature ◽  
Crack Growth ◽  
Evaluation Research ◽  
Fatigue Cracking ◽  
Experimental Investigations ◽  
Damage Evaluation ◽  
Cracking Behavior ◽  
Growth Crack ◽  
Small Crack Growth

Experimental investigations of fatigue cracking behavior of LC9 aluminum alloy (AA LC9) subjected to elevated temperature were conducted with scanning electron microscope (SEM). Results indicate elevated temperature is important for the fatigue crack growth of AA LC9. Based on small crack growth, crack growth rate for AA LC9 is characterized.

SEM In Situ Investigation on Fatigue Cracking Behavior of X80 Pipeline Steel with Inclusions

2011 ◽  
Vol 284-286 ◽  
pp. 1096-1100 ◽  
Author(s):  
Ke Tong ◽  
Yan Ping Zeng ◽  
Xin Li Han ◽  
Yao Rong Feng ◽  
Xiao Dong He
Keyword(s):  
Crack Initiation ◽  
Pipeline Steel ◽  
Fatigue Cracking ◽  
Fatigue Loading ◽  
In Situ Observation ◽  
X80 Pipeline Steel ◽  
Cracking Behavior ◽  
The Matrix ◽  
Extension Period

The micro-mechanical behavior of inclusions in X80 pipeline steel under fatigue loading was investigated by means of SEM in situ observation. The influence of sizes and shapes of inclusion on crack initiation and propagation was analyzed. The result shows that for large-size single-particle inclusion, cracks initiate from the interior under the fatigue loading. When a certain circulation cycles are reached, cracks initiate at the matrix near the sharp corner of the inclusion. The cracks extend at the matrix during the stable extension period and unstable extension period following the crack initiation, until fracture occurred. For chain inclusion, cracks first initiate at the interface between inclusion and matrix within the chain area, and the circulation cycles needed for initiation are far less than single inclusion. Cracks steadily extend after the initiation, and then fracture after very short circulation cycles. A chain of inclusion with the shape corners is serious harmful to the fatigue properties.

scholarly journals STUDI EXPERIMENTAL FATIK KOROSI ALUMINIUM PADUAN 7075-T6 PADA LINGKUNGAN 3,5% NaCl DENGAN INHIBITOR Na2CrO4

POROS ◽  
2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Priyani Budiyarti Budiyarti
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Rate ◽  
Fatigue Testing ◽  
Fatigue Cracking ◽  
Aircraft Industry ◽  
Good Resistance ◽  
Microstructure Observation ◽  
Corrosion Propagation ◽  
Optical Microstructure ◽  
Rate Test

AA7075-T6 aluminum alloy is a material that widely used in the aircraft industry because aluminum as a lightweight metal, good machinability, good corrosion resistance and good castability and non-magnetic metals. Aluminum also has high tenacity, is easy to form and is easy to connect. Aluminum has good resistance to corrosion, however aluminum has effect to corrosion if it is on corrosive environment including AA7075-T6 aluminum alloy which used in the aircraft industry. Inhibitor is used to control a corrosion. The aims of these researchs were to investigate the effect of inhibitors on corrosion rates and the rate of fatigue crack corrosion propagation on AA7075-T6 aluminum alloys. This research is used Na2CrO4 inhibitors with variety of concentrations of 0.1%, 0.3%, 0.5% and 0.7% added to 3.5% NaCl solution. Corrosion rate test is used a method of potential dynamic polarization. Corrosion fatigue testing is carried out with constant amplitude at a frequency of 10 Hz and a voltage ratio (R) 0.1. Specimens were used cracked specimen centers (CCT) on orientation in the direction of rolling. The supporting data of the research were the mechanical properties of the material included optical microstructure observation, tensile testing and hardness testing. The results have shown that the optimal concentration of Na2CrO4 inhibitors was achieved at 0.5% which was characterized by a decreasing in corrosion rate and slower corrosion rate of fatigue cracking.

STEM investigations of the influence of copper on alumina scale detachment during in-situ wetting experiments of Al-7Si-0.3Mg alloy with 95Sn-5Cu filler metal

2021 ◽  
Vol 112 (5) ◽  
pp. 415-421
Author(s):  
Ashok Vayyala ◽  
Anke Aretz ◽  
Kirsten Bobzin ◽  
Wolfgang M. Wietheger ◽  
Julian Hebing ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Filler Metal ◽  
Base Material ◽  
Alumina Scale ◽  
Alumina Layer ◽  
Liquid Filler ◽  
Scanning Electron

Abstract Aluminum alloys have a strong tendency to form alumina layers on their surfaces when exposed to atmospheric air, even at room temperature. This is a severe challenge for brazing aluminum alloys as the alumina layer acts as a diffusion barrier and hinders the interactions between the filler metal and the base material. In order to achieve a good metallurgical bond between the filler metal and the aluminum alloy, it is of crucial importance to remove the alumina layer as well as to simultaneously prevent further oxidation of the aluminum alloy. The current investigation focuses on the detailed micro-structural changes that occur during in-situ brazing of liquid filler metal, 95Sn-5Cu (wt.%) on an aluminum alloy, Al-7Si-0.3Mg. These in-situ studies were performed in a large chamber scanning electron microscope in order to monitor the interactions of the filler metal and the base material, particularly the role of Cu on alumina detachment. After the in-situ experiments, the local surface and cross-sectional regions were analyzed by scanning electron microscopy in conjunction with energy dispersive X-ray spectroscopy to understand the variation in chemistry across the wetted region, which includes the interfacial region between filler metal and the base material. As the alumina scale present on the aluminum alloy is very thin (<50 nm), nanoscale characterization techniques such as transmission electron microscopy in scanning mode, including selected area electron diffraction for crystal structure determination, were performed. From this investigation, it was found that the Cu in liquid filler metal diffuses into the base material via the oxide layer, resulting in the formation of Al2Cu intermetallic precipitates.

Life Prediction of Aluminum Alloy Structure Subjected to Corrosion Fatigue and Corrosion Damage

2012 ◽  
Vol 166-169 ◽  
pp. 1887-1890
Author(s):  
You Hong Zhang ◽  
Qian Zhang ◽  
Xin Long Chang ◽  
Chun Guo Yue ◽  
Shi Ying Zhang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Fatigue ◽  
Life Prediction ◽  
Corrosion Damage ◽  
Simulation Method ◽  
Life Cycles ◽  
Ansys Software ◽  
Alloy Structure ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth

The strength of the aging structure deteriorates mainly as a result of corrosion and fatigue damage. In this paper, the life prediction methods of corroded and corrosion fatigued aluminum alloy structure were proposed. The stress multiplication of aluminum alloy structure subjected to corrosion damage was simulated by ANSYS software. We proposed the AFGROW software simulation method to predicate the numerical simulation of corrosion fatigue crack growth. At last, the life cycles of structures subjected to corrosion damage and corrosion fatigue were estimated, and a very good performance of the proposed methods are achieved after validation with the experimental data.

Fatigue cracking behavior of 6063 aluminum alloy for fitting clamps of overhead conductor lines

2015 ◽  
Vol 88 ◽  
pp. 478-484 ◽  
Author(s):  
L.R. Zeng ◽  
Z.M. Song ◽  
X.M. Wu ◽  
C.H. Li ◽  
G.P. Zhang
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Cracking ◽  
Cracking Behavior ◽  
6063 Aluminum Alloy

Environment-induced fatigue cracking behavior of aluminum alloys and modification methods

2015 ◽  
Vol 33 (3-4) ◽  
pp. 119-137 ◽  
Author(s):  
Xi-Shu Wang ◽  
Xu-Dong Li ◽  
Hui-Hui Yang ◽  
Norio Kawagoishi ◽  
Pan Pan
Keyword(s):  
Fatigue Strength ◽  
Aluminum Alloys ◽  
Corrosion Fatigue ◽  
Residual Life ◽  
Engineering Application ◽  
Fatigue Cracking ◽  
Local Stress ◽  
Fatigue Loading ◽  
Propagation Length ◽  
Cracking Behavior

AbstractThis paper reviews the current corrosion fatigue strength issues of light metals, which include the corrosion fatigue cracking behaviors, such as the prior-corrosion pit deformation mechanism, the synergistic interaction between prior-corrosion pits and local stress/strain, the coupling damage behavior under mechanical fatigue loading, and the surrounding environmental factors such as a high humidity and a current 3.5 wt.% or 5.0 wt.% NaCl aqueous solution. The characterization of corrosion fatigue crack growth rate based on simple and measurable parameters (crack propagation length and applied stress amplitude or stress intensity factor) is also of great concern in engineering application. In addition, an empirical model to predict S-N curves of aluminum alloys at the environmental conditions was proposed in this paper. One of the main aims was to outline the corrosion fatigue cracking mechanism, which favors the corrosion fatigue residual life prediction of aluminum alloys subjected to the different environmental media that are often encountered in engineering services. Subsequently, this paper explores recently various surface modification technologies to enhance corrosion fatigue resistance and to improve fatigue strength. For example, the fatigue strength of 2024-T4 aluminum alloy has been modified using plasma electrolytic oxidation coating with the impregnation of epoxy resin modification method to compare with other oxide coating or uncoated substrate alloy.

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