Effect of Preexisting Corrosion on Fatigue Cracking of Aluminum Alloys 2024-T3 and 7075-T6

1995 ◽  
Author(s):  
Gerhardus H. Koch ◽  
Elise L. Hagerdorn ◽  
Alan P. Berens
Keyword(s):  
Aluminum Alloys ◽  
Fatigue Cracking

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.

Analytical Electron Microscopy Study of Second-Phase Particles in 7075 and 7475 Aluminum Alloys

1985 ◽  
Vol 43 ◽  
pp. 348-349
Author(s):  
M. Raghavan ◽  
J. Y. Koo ◽  
J. W. Steeds ◽  
B. K. Park
Keyword(s):  
Aluminum Alloys ◽  
Silicon Oxide ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Partial Substitution ◽  
Second Phase ◽  
X Ray ◽  
Second Phase Particles ◽  
Almost All

X-ray microanalysis and Convergent Beam Electron Diffraction (CBD) studies were conducted to characterize the second phase particles in two commercial aluminum alloys -- 7075 and 7475. The second phase particles studied were large (approximately 2-5μm) constituent phases and relatively fine ( ∼ 0.05-1μn) dispersoid particles, Figures 1A and B. Based on the crystal structure and chemical composition analyses, the constituent phases found in these alloys were identified to be Al7Cu2Fe, (Al,Cu)6(Fe,Cu), α-Al12Fe3Si, Mg2Si, amorphous silicon oxide and the modified 6Fe compounds, in decreasing order of abundance. The results of quantitative X-ray microanalysis of all the constituent phases are listed in Table I. The data show that, in almost all the phases, partial substitution of alloying elements occurred resulting in small deviations from the published stoichiometric compositions of the binary and ternary compounds.

Identification of the characteristic length scale for fatigue cracking in fretting contacts

1998 ◽  
Vol 08 (PR8) ◽  
pp. Pr8-159-Pr8-166 ◽  
Author(s):  
S. Fouvry ◽  
Ph. Kapsa ◽  
F. Sidoroff ◽  
L. Vincent
Keyword(s):  
Characteristic Length ◽  
Fatigue Cracking ◽  
Length Scale ◽  
Characteristic Length Scale

Electrochemical Impedance Characteristics of Sintered 7075 Aluminum Alloy Under Ssrt Condition

2013 ◽  
Vol 58 (2) ◽  
pp. 505-508 ◽  
Author(s):  
S. Sunada ◽  
N. Nunomura
Keyword(s):  
Aluminum Alloys ◽  
Complex Shape ◽  
Electrochemical Impedance ◽  
Ingot Metallurgy ◽  
View Point ◽  
Corrosion Properties ◽  
Electrochemical Tests ◽  
Impedance Characteristics ◽  
Polarization Test ◽  
Conventional Ingot

Powder metallurgy (P/M) process has the advantage of better formability to fabricate complex shape products without machining and welding. And recently this P/M process has been applied to the production of aluminum alloys. The P/M aluminum alloys thus produced also have received considerable interest because of their fine and homogeneous structure. Many papers have been published on the mechanical properties of the aluminum alloys produced by P/M process while there have been few on their corrosion properties from the view point of electrochemistry. In this experiment, therefore, two kinds of 7075 aluminum alloys prepared by the conventional ingot metallurgy (I/M) process and P/M process were used, I/M material is commercially available. and their corrosion behavior were investigated through the electrochemical tests such as potentiodynamic polarization test, slow rate strain tensile (SSRT) test and electrochemical impedance spectroscopy (EIS) measurement under SSRT test in the corrosion solution and the deionized water.

Cold Retrofit Method Study for Fatigue Cracking of Steel Bridge

2015 ◽  
Vol 105 (23) ◽  
pp. 1-8 ◽  
Author(s):  
Chun-sheng Wang ◽  
Chang-yang Ou ◽  
Mu-sai Zhai ◽  
Lan Duan
Keyword(s):  
Fatigue Cracking ◽  
Steel Bridge
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