Analysis of Nanoprecipitation Effect on Toughness Behavior in Warm Worked AA7050 Alloy

Commonly adopted main methods aimed to improve the strength–toughness combination of high strength aluminum alloys are based on a standard process. Such a process includes alloy solution heat treatment, water-quench and reheating at controlled temperature for ageing holding times. Some alloys request an intermediate cold working hardening step before ageing for an optimum strength result. Recently a warm working step has been proposed and applied. This replaces the cold working after solution treatment and quenching and before the final ageing treatment. Such an alternative process proved to be very effective in improving strength–toughness behavior of 7XXX aluminum alloys. In this paper the precipitation state following this promising process is analyzed and compared to that of the standard route. The results put in evidence the differences in nanoprecipitation densities that are claimed to be responsible for strength and toughness improved properties.

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Experimental Factors Concerning X-Ray Residual Stress Measurements in High-Strength Aluminum Alloys

Advances in X-ray Analysis ◽

10.1154/s037603080000447x ◽

1966 ◽

Vol 10 ◽

pp. 284-294

Author(s):

Michael E. Hilley ◽

James J. Wert ◽

Robert S. Goodrich

Keyword(s):

Aluminum Alloys ◽

Cold Working ◽

High Strength ◽

Tensile Tests ◽

Second Phase ◽

X Ray Diffraction ◽

Nondestructive Technique ◽

Angular Rotation ◽

X Ray ◽

High Strength Aluminum Alloys

AbstractX-ray diffraction as a means of determining stresses has found increasing application in the last few years. This is primarily because it is the only technique by which stresses can be determined without making measurements on the specimen or structure in the unstressed condition and, consequently, it is the only truly nondestructive technique for determining residual stresses. The principles of determining macrostresses on surfaces with commercially available equipment is quite well known and employs either the X-ray diffractometer or back-reflect ion camera techniques. The diffractometer technique was selected for this investigation because of its accuracy and because it allows both macrostresses and microstra in to be analyzed from the change in position and shape of the diffraction peaks. The X-ray analysis actually consisted of two separate phases. The first dealt with the X-ray determination of the elastic constants (Young's modulus and Poisson 's ratio) for several aluminum alloys, including 5083. These values were compared with the theoretical or published values as determined by standard tensile tests and used later in stress calculations. For these tests, a unique stress stage was used which allowed the specimen to be stressed while positioned in the diffractometer, and also have angular rotation about the diffractometer axis that is independent of the rotation of the counter and receiving slit system. The second phase consisted of analyzing different groups of 5083—aluminum alloy specimens which had been subjected to various degrees of cold working by rolling. This analysis consisted not only of the computation of macrostresses, but also of microstrain and change in particle size as a function of percentage reduction in thickness. The final portion of this phase dealt with electro polishing successive layers from the surface of each sample and relating the measured relaxation to the thickness of the layers removed. In this way, stress distribution in depth was obtainable as a function of cold working.

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The Effect of Microstructure on the Properties of High Strength Aluminum Alloys

10.21236/ada133997 ◽

1983 ◽

Author(s):

Edgar A. Starke ◽

Keyword(s):

Aluminum Alloys ◽

High Strength ◽

High Strength Aluminum Alloys ◽

Effect Of Microstructure

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Surface Modification of Aluminum 6061-O Alloy by Plasma Electrolytic Oxidation to Improve Corrosion Resistance Properties

Coatings ◽

10.3390/coatings11010004 ◽

2020 ◽

Vol 11 (1) ◽

pp. 4

Author(s):

Dmitry V. Dzhurinskiy ◽

Stanislav S. Dautov ◽

Petr G. Shornikov ◽

Iskander Sh. Akhatov

Keyword(s):

Corrosion Resistance ◽

Aluminum Alloy ◽

Aluminum Alloys ◽

Plasma Electrolytic Oxidation ◽

Electrochemical Impedance ◽

High Strength ◽

Electrolytic Oxidation ◽

Coating Layers ◽

Plasma Electrolytic ◽

High Strength Aluminum Alloys

In the present investigation, the plasma electrolytic oxidation (PEO) process was employed to form aluminum oxide coating layers to enhance corrosion resistance properties of high-strength aluminum alloys. The formed protective coating layers were examined by means of scanning electron microscopy (SEM) and characterized by several electrochemical techniques, including open circuit potential (OCP), linear potentiodynamic polarization (LP) and electrochemical impedance spectroscopy (EIS). The results were reported in comparison with the bare 6061-O aluminum alloy to determine the corrosion performance of the coated 6061-O alloy. The PEO-treated aluminum alloy showed substantially higher corrosion resistance in comparison with the untreated substrate material. A relationship was found between the coating formation stage, process parameters and the thickness of the oxide-formed layers, which has a measurable influence on enhancing corrosion resistance properties. This study demonstrates promising results of utilizing PEO process to enhance corrosion resistance properties of high-strength aluminum alloys and could be recommended as a method used in industrial applications.

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Accelerated discovery of high-strength aluminum alloys by machine learning

Communications Materials ◽

10.1038/s43246-020-00074-2 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Jiaheng Li ◽

Yingbo Zhang ◽

Xinyu Cao ◽

Qi Zeng ◽

Ye Zhuang ◽

...

Keyword(s):

Machine Learning ◽

Aluminum Alloys ◽

Mechanical Performance ◽

High Strength ◽

Cost Effective ◽

Alloy System ◽

Processing Route ◽

Specific Strength ◽

Cu Alloy ◽

High Strength Aluminum Alloys

Abstract Aluminum alloys are attractive for a number of applications due to their high specific strength, and developing new compositions is a major goal in the structural materials community. Here, we investigate the Al-Zn-Mg-Cu alloy system (7xxx series) by machine learning-based composition and process optimization. The discovered optimized alloy is compositionally lean with a high ultimate tensile strength of 952 MPa and 6.3% elongation following a cost-effective processing route. We find that the Al8Cu4Y phase in wrought 7xxx-T6 alloys exists in the form of a nanoscale network structure along sub-grain boundaries besides the common irregular-shaped particles. Our study demonstrates the feasibility of using machine learning to search for 7xxx alloys with good mechanical performance.

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