Selective dissolution during acid pickling of aluminum alloys by element-resolved electrochemistry

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118618 ◽

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.

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Fabrication and Estimation of an Ultrafine Grained Complex Aluminum Alloy Sheet by the ARB Process Using Dissimilar Aluminum Alloys

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2011.49.11.893 ◽

2011 ◽

Vol 49 (11) ◽

Keyword(s):

Aluminum Alloy ◽

Aluminum Alloys ◽

Alloy Sheet ◽

Aluminum Alloy Sheet ◽

Complex Aluminum ◽

Dissimilar Aluminum Alloys ◽

Ultrafine Grained

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Quality monitoring system for a pulsed micro welding process on aluminum alloys

International Congress on Applications of Lasers & Electro-Optics ◽

10.2351/1.5063071 ◽

2014 ◽

Author(s):

Daniel Albrecht ◽

Philipp von Witzendorff ◽

Oliver Suttmann ◽

Ludger Overmeyer

Keyword(s):

Aluminum Alloys ◽

Monitoring System ◽

Welding Process ◽

Quality Monitoring

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Electrochemical Impedance Characteristics of Sintered 7075 Aluminum Alloy Under Ssrt Condition

Archives of Metallurgy and Materials ◽

10.2478/amm-2013-0027 ◽

2013 ◽

Vol 58 (2) ◽

pp. 505-508 ◽

Cited By ~ 2

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.

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