Download or read book Effect of Microstructure and Environment on Stress Corrosion of 7075 Aluminum Alloy written by G. Geschwind and published by . This book was released on 1973 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grain boundary microstructure as well as the pH in a chloride ion solution environment was found to be significant to stress corrosion attack in 7075 aluminum alloys. The influence of these factors on both the initiation and propagation of cracking and the mode of attack in these alloys are described. Microstructural modifications to attain desirable stress corrosion resistance are suggested.
Download or read book Influence of Microstructure on the Mechanical Properties and Stress Corrosion Susceptibility of 7075 Aluminum Alloy written by Philip Adler and published by . This book was released on 1971 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Matrix and grain boundary features were systematically varied, using appropriate heat treatment, to evaluate their significance in changing the mechanical and stress corrosion properties of 7075 aluminum alloy. Maximum strength is associated with a Guinier-Preston zone matrix. The precipitate-free-zone adjacent to high angle grain boundaries was found to have only a slight effect on yield and tensile strength and a greater influence on hardness. Stress corrosion susceptibility was studied in a chloride ion environment over a 0.7 - 3.5 pH range. Differences in pH-dependent susceptibility associated exclusively with grain boundary structure for material of highest strength were observed. Grain boundary precipitate spacing (inversely related to precipitate density) was found to be of primary importance to susceptibility. The relative importance of crack initiation to the over-all stress corrosion process was also found to be dependent on grain boundary microstructure. These results indicate that improved properties for Al-Mg-Zn type alloys can be attained by a desirable combination of matrix and grain boundary structure. (Author).
Download or read book Effect of Microstructure on the Yield Strength and Stress Corrosion Resistance of 7075 Aluminium Alloy written by M. Hua and published by . This book was released on 1990 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Fracture Mechanics Study of Corrosion Fatigue written by R. A. M. Chandra Prasad and published by . This book was released on 2022-09-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Majority of industrial components fail due to the conjoint actions of fatigue and corrosion. All fatigue failures including one in air can be categorized as corrosion fatigue. Absolute fatigue can take place only in vacuum or inert environment. The effect of corrosion on fatigue has been extensively studied by determining the stress vs. number of cycles (S-N) curve. S-N curve depicts the final fracture, it does not separate the crack initiation and crack propagation. The defect tolerant design based on fracture mechanics concepts assumes that some forms of defects are already present in the materials and a considerable life in spent in crack propagation before the final fracture. Measure of resistance of a material to crack growth (fracture toughness) then becomes extremely important. It is now possible to describe material property of fracture toughness in terms of applied intensity of stress near the crack tip (K). Fracture mechanics based on elastic material behavior (absence of significant yielding) , referred to as the linear elastic fracture mechanics (LEFM) is well suited to materials which have limited ductility. The stress intensity factor (K ) is used both for conditions of static loading (Stress Corrosion Cracking) and for the moving cracks during fatigue loading . In this book the results of corrosion fatigue crack growth on 7075 - Alclad alloy are presented. This alloy is widely used in aircraft and automobile industries. Corrosion resistance is obtained by cladding with a more corrosion resistant aluminum alloy. However, the corrosion protection system may undergo rupture especially during crack growth in the underlying metal. Environment will then play a dominant role in the crack growth process. The design of reliable aircraft structures requires provision that cracks do not propagate under cyclic loading to reach a critical size resulting in fracture. The understanding of crack propagation under the conjoint action of corrosion and fatigue is thus of great technological and economic significance. Conflicting observations have been reported in literature regarding the influence of microstructure and environmental variables on the corrosion crack propagation rates.
Download or read book Stress corrosion Cracking of Aluminum Alloys written by F. H. Haynie and published by . This book was released on 1966 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report deals with the stress-corrosion cracking of aluminum alloys, and it represents an effort by DMIC to expand on the information contained in DMIC Memorandum 202, 'Stress-Corrosion Cracking of Aluminum Alloys', dated February 15, 1965. DMIC Report 228 begins by presenting a comprehensive definition of stress-corrosion cracking. This is followed by sections dealing with (1) the historical development and growth in awareness of the problem, (2) the mechanisms involved, and (3) the theory of stress-corrosion cracking. A section on experimental techniques is presented. These techniques include test methods used to determine the susceptibility of alloys to stress-corrosion cracking, as well as more refined methods of studying the fundamental mechanisms of the problem. Different evaluation methods, applicable to obtaining the different objectives of stress-corrosion testing, are also presented. All of the foregoing serve as background to the sections on stress-corrosion-cracking behavior of aluminum alloys and preventive measures. (Author).
Download or read book Effect of Microstructure on Pit to Crack Transition of 7075 T6 Aluminum Alloy written by Kimberli Jones and published by . This book was released on 2006 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this research was to gain an increased understanding of how microstructure influences pit growth, pit-to-crack transition, and critical crack propagation to fracture. Two thicknesses of 7075-T6 aluminum alloy were etched and subjected to corrosion fatigue in a 3.5 % sodium chloride environment. 7075-T6 aluminum alloy is of particular interest to the aging aircraft community, as this alloy has been used extensively on wing and fuselage structures for both military and commercial aircraft in the past. Testing was interrupted at various intervals to obtain information on pit generation, growth, and potential cracking. Results indicated that microstructure has a significant influence on pit-to-crack transition and fatigue crack propagation. Short cracks (
Download or read book Research on the Basic Nature of Stress Corrosion for Various Structural Alloys at Room and Elevated Temperatures written by Frank A. Crossley and published by . This book was released on 1963 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Program objectives were: (1) to study the effect of microstructure on susceptibility to stress corrosion cracking in the short-transverse direction of 7075-T6 aluminum alloy; and (2) to study the kinetics of stress-corrosion cracking at elevated temperature of candidate materials for structural applications in the trisonic transport in the presence of sea salt. It was hypothesized that the poor resistance to stress corrosion of high-strength, wrought aluminum alloys was due to the layered-type microstructure characteristic of these materials. Short life was associated with the layered-type of grain structure characteristic of commercial material, and long life was associated with irregular or equiaxed grain structures. The experimental results gave good support to the hypothesis.
Download or read book Stress Corrosion Cracking of Wrought and P M High Strength Aluminum Alloys written by A. W. Thompson and published by . This book was released on 1986 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major findings from a comprehensive study on the role of microstructure on the susceptibility to environmental embrittlement of high strength aluminum alloys are presented and discussed. Most of the studies used commercial 7075, or a high purity equiaxed version, HP7075, or a similar powder version 7090. Through the innovative use of loading mode and straining electrode test, stress corrosion cracking was shown to be controlled by the introduction and internal distribution of hydrogen, particularly to grain boundaries. This was the case for the underaged and peak aged microstructures, with the latter being the most susceptible. The SCC behavior of the even more resistant overaged microstructure was shown to be controlled by anodic dissolution processes, predominantly associated with slip bands. Aluminum alloys were also shown to be susceptible to embrittlement under conditions of cathodic polarization correcting a widely held belief that concomitant anodic processes are required. Studies using controlled microstructures were able to rank the importance of different microstructural features to help develop alloy design strategies for more environmentally resistant alloys--the most effective features are those grain interior precipitates which promote fine, homogeneous slip either by reduced particle cutting or enhanced dislocation generation; fine, grain boundary precipitate free zones were found not to be very important, except in their role in reducing the local strength of the boundary region.
Download or read book Environmental Corrosion fatigue Behavior of Aluminum Alloys written by D. N. Williams and published by . This book was released on 1970 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of environment on fatigue behavior are quite intimately related to such test variables as stress intensity, cyclic frequency, and temperature. The effect of these variables has been shown to be quite complex. However, a consistent pattern of behavior is beginning to emerge which, it is hoped, will lead to a considerably changed understanding of the corrosion-fatigue process. It is considered probable that an increased understanding of the corrosion-fatigue process will also contribute measureably to an improved understanding of general fatigue processes. Material variables such as composition, directionality of properties, and microstructure, have important effects on corrosion-fatigue behavior of aluminum alloys. However, it appears that these variables, at least in gaseous environments, may be important largely because of their effects on the mechanical behavior of aluminum alloys. On the other hand, studies in seawater suggest that these variables become increasingly important as the corrosive nature of the environment increases. This memorandum discusses in detail the effects of both test variables and material variables on corrosion fatigue. In addition, current theories of corrosion-fatigue mechanisms are outlined, and several methods of preventing corrosion fatigue are suggested. (Author).
Download or read book Microstructural Characterization and Corrosion Behavior of Al 7075 Alloys Using X ray Synchrotron Tomography written by Sudhanshu Shekhar Singh and published by . This book was released on 2015 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Al 7075 alloys are used in a variety of structural applications, such as aircraft wings, automotive components, fuselage, spacecraft, missiles, etc. The mechanical and corrosion behavior of these alloys are dependent on their microstructure and the environment. Therefore, a comprehensive study on microstructural characterization and stress-environment interaction is necessary. Traditionally, 2D techniques have been used to characterize microstructure, which are inaccurate and inadequate since the research has shown that the results obtained in the bulk are different from those obtained on the surface. There now exist several techniques in 3D, which can be used to characterize the microstructure. Al 7075 alloys contain second phase particles which can be classified as Fe-bearing inclusions, Si-bearing inclusions and precipitates. The variation in mechanical and corrosion properties of aluminum alloys has been attributed to the size, shape, distribution, corrosion properties and mechanical behavior of these precipitates and constituent particles. Therefore, in order to understand the performance of Al 7075 alloys, it is critical to investigate the size and distribution of inclusions and precipitates in the alloys along with their mechanical properties, such as Young's modulus, hardness and stress-strain behavior. X-ray tomography and FIB tomography were used to visualize and quantify the microstructure of constituent particles (inclusions) and precipitates, respectively. Microscale mechanical characterization techniques, such as nanoindentation and micropillar compression, were used to obtain mechanical properties of inclusions. Over the years, studies have used surface measurements to understand corrosion behavior of materials. More recently, in situ mechanical testing has become more attractive and advantageous, as it enables visualization and quantification of microstructural changes as a function of time (4D). In this study, in situ X-ray synchrotron tomography was used to study the SCC behavior of Al 7075 alloys in moisture and deionized water. Furthermore, experiments were performed in EXCO solution to study the effect of applied stress on exfoliation behavior in 3D. Contrary to 2D measurements made at the surface which suggest non-uniform crack growth rates, three dimensional measurements of the crack length led to a much more accurate measurement of crack growth rates.
Download or read book Stress Corrosion Cracking written by V S Raja and published by Elsevier. This book was released on 2011-09-22 with total page 817 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of stress corrosion cracking (SCC), which causes sudden failure of metals and other materials subjected to stress in corrosive environment(s), has a significant impact on a number of sectors including the oil and gas industries and nuclear power production. Stress corrosion cracking reviews the fundamentals of the phenomenon as well as examining stress corrosion behaviour in specific materials and particular industries. The book is divided into four parts. Part one covers the mechanisms of SCC and hydrogen embrittlement, while the focus of part two is on methods of testing for SCC in metals. Chapters in part three each review the phenomenon with reference to a specific material, with a variety of metals, alloys and composites discussed, including steels, titanium alloys and polymer composites. In part four, the effect of SCC in various industries is examined, with chapters covering subjects such as aerospace engineering, nuclear reactors, utilities and pipelines. With its distinguished editors and international team of contributors, Stress corrosion cracking is an essential reference for engineers and designers working with metals, alloys and polymers, and will be an invaluable tool for any industries in which metallic components are exposed to tension, corrosive environments at ambient and high temperatures. Examines the mechanisms of stress corrosion cracking (SCC) presenting recognising testing methods and materials resistant to SCC Assesses the effect of SCC on particular metals featuring steel, stainless steel, nickel-based alloys, magnesium alloys, copper-based alloys and welds in steels Reviews the monitoring and management of SCC and the affect of SCC in different industries such as petrochemical and aerospace
Download or read book The Effect of Potential on the Stress Corrosion Cracking of Aluminum Alloy 7075 written by Anh Hong Le and published by . This book was released on 1982 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Microstructure on the Stress corrosion Susceptibility of an Al Zn Mg Alloy written by Anthony J. DeArdo (Jr.) and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microstructure Evolution in Metal Forming Processes written by J Lin and published by Elsevier. This book was released on 2012-07-09 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monitoring and control of microstructure evolution in metal processing is essential in developing the right properties in a metal. Microstructure evolution in metal forming processes summarises the wealth of recent research on the mechanisms, modelling and control of microstructure evolution during metal forming processes. Part one reviews the general principles involved in understanding and controlling microstructure evolution in metal forming. Techniques for modelling microstructure and optimising processes are explored, along with recrystallisation, grain growth, and severe plastic deformation. Microstructure evolution in the processing of steel is the focus of part two, which reviews the modelling of phase transformations in steel, unified constitutive equations and work hardening in microalloyed steels. Part three examines microstructure evolution in the processing of other metals, including ageing behaviour in the processing of aluminium and microstructure control in processing nickel, titanium and other special alloys. With its distinguished editors and international team of expert contributors, Microstructure evolution in metal forming processes is an invaluable reference tool for metal processors and those using steels and other metals, as well as an essential guide for academics and students involved in fundamental metal research. Summarises the wealth of recent research on the mechanisms, modelling and control of microstructure evolution during metal forming processes Comprehensively discusses microstructure evolution in the processing of steel and reviews the modelling of phase transformations in steel, unified constitutive equations and work hardening in microalloyed steels Examines microstructure evolution in the processing of other materials, including ageing behaviour in the processing of aluminium
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Precipitation Heat Treatment on the Microstructure Toughness and Stress Corrosion Crack Propagation Resistance of Aluminum Alloy 2020 written by John George Rinker and published by . This book was released on 1982 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Microstructure on Pit to crack Transition of 7075 T6 Aluminum Alloy written by Kimberli Jones and published by . This book was released on 2004 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
