Author: G. L. Hanna
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 84
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Book Description
The influence of work hardening exponent on the variation of fracture toughness with material thickness was studied for high strength steel, aluminum, and titanium alloys. A variety of materials could be compared by employing normalizing parameters to represent the toughness in terms of the relative plastic zone size and representing the relationship on a logarithmic plot. Using this method the normalized fracture toughness parameter in the region of 100% slant fracture was proportional to the square of the work hardening exponent for the body-centered cubic metals. In the fracture mode transition region, however low work hardening was beneficial and the thickness at which the transition occurred decreased as the work hardening exponent increased. The influence of work hardening exponent on cyclically-induced crack growth rates in AISI 4340 steel and 13V-11Cr-3A1 titanium was also evaluated. In the steel the growth rate was slightly less for the material with the lower work hardening exponent while the titanium exhibited so significant trend as a function of work hardening characteristics. The specimen thickness had the greatest effect on the cyclically-induced crack growth with decreased growth rates present in the thicker specimens. Attempts were also made to control the process zone size by adding zirconia particles to a high strength steel matrix through powder metallurgy techniques.
Author: F. J. Lauta
Publisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 41
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Book Description
Ths influence of work hardening exponent on the fracture toughness of 4340, 18% nickel maraging, and AM-355 stainless steel was studied. In most cases the effects produced by variations in work hardening were difficult to analyze due to accompanying changes in yield strength and microstructure. In this investigation the transition in fracture mode induced by varying section size was used as a basic evaluation method since complicating effects due to yield strength changes were not introduced. The results indicated that the transition from flat to shear failures occurred in larger section sizes in the material with the lower work hardening exponent. Once full shear failures were obtained, however, materials with higher work hardening coefficients required greater energy to produce failure. The influence of work hardening on the transition behavior could be rationalized on the basis of the larger plastic zone present in the steel with the lower strain hardening coefficient. Although useful correlations between the strain hardening index and the fracture mode transition could be obtained no quantitative relationship between work hardening exponent, as defined by strain to maximum load, and plane strain fracture toughness was evident. (Author).
Author: Naval Research Laboratory (U.S.)
Publisher:
ISBN:
Category : Naval research
Languages : en
Pages : 562
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Book Description
Author: Dennis Michael Tracey
Publisher:
ISBN:
Category : Ductility
Languages : en
Pages : 36
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Book Description
The growth and coalescence of voids is a common mechanism of fracture in ductile materials. Analytical work on the problem to date has dealt mainly with isolated voids in perfectly plastic materials, so that strain hardening and interactions between neighboring voids have been neglected. These features of void growth are examined here, but only for a simple geometrical configuration. In particular, the growth of single infinitely long cylindrical voids in bodies of rigid-plastic, strain-hardening material is considered. Bodies with both finite and infinite dimensions normal to the void surface are included in the analysis. The exact relation among the pertinent variables: transverse stress, axial strain, hardening coefficient, void strain and void growth rate is presented. Solution via a bounding technique is given for two general cases. The first case is that of an imposed constant void growth rate and the second case is an imposed constant transverse stress. The results show a decelerating effect of hardening on void growth. Application to the ductile fracture problem of void growth in the neck of a tensile specimen demonstrates the accelerating effect of void growth due to interactions between voids. (Author).
Author: Defense Documentation Center (U.S.)
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 784
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Book Description
Author:
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 200
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Book Description
Technical reports published by the Air Force Materials Laboratory during the period 1 July 1964 - 30 June 1965 are abstracted herein. Reports on research conducted by the Air Force Materials Laboratory personnel as well as that conducted on contract are included.
Author: American Institute of Mining, Metallurgical, and Petroleum Engineers
Publisher:
ISBN:
Category : Mineral industries
Languages : en
Pages : 1232
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Book Description
Some vols., 1920-1949, contain collections of papers according to subject.
Author: H. R. Voorhees
Publisher: ASTM International
ISBN: 9780803100626
Category : Alloys
Languages : en
Pages : 305
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Book Description
Author: Metallurgical Society of AIME.
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1200
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Book Description
Author: Erik Lassner
Publisher: Springer Science & Business Media
ISBN: 1461549078
Category : Science
Languages : en
Pages : 432
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Book Description
Why does someone write a book about Tungsten? There are several reasons and precedents for this, the most important of which is that the last book on tungsten was written more than 20 years ago, in 1977, by St. W H. Yih and Ch T. Wang. During the intervening period there have been many new scientific and technological developments and innova tions, so it was not only our opinion but the view of many other members of the "tungsten family" that it was time to start writing a new book about tungsten. Preparations of the new book began in 1994. further impetus to the project was provided by the realization that in spite of this new knowledge having been presented at seminars or published in the technical press, a general acknowledgement of it by the majority of technicians and scientists is still far from being realized. It is our hope that this book will significantly contribute to a broader acceptance of recent scientific and technological innovations. An important prerequisite for such a project is the availability of a recently retired, experienced person willing to devote his time and talents to the tedious part of the exercise.
