Analysis of certain problems of the brittle fracture of bcc metals

B. Z. Margolin; V. A. Shvetsova; M. A. Sergeeva

doi:10.1007/bf02208785

Parameter Representation of Low-Temperature Yield Behavior of Body-Centered Cubic Transition Metals

Journal of Basic Engineering ◽

10.1115/1.3645890 ◽

1966 ◽

Vol 88 (2) ◽

pp. 518-524 ◽

Cited By ~ 60

Author(s):

P. E. Bennett ◽

G. M. Sinclair

Keyword(s):

Low Temperature ◽

Transition Metals ◽

Brittle Fracture ◽

Yield Strength ◽

Strain Rate ◽

Body Centered Cubic ◽

Yield Behavior ◽

Bcc Metals ◽

State Of Stress ◽

Iron Chromium

In the low-temperature range, the engineering yield strength of polycrystalline bcc metals can change by a factor of 10 or more with serious consequences appearing in the form of catastrophic brittle fracture. Engineering variables known to have an important effect on the yield behavior are state of stress, temperature, loading or strain rate, composition, and microstructure. For iron, chromium, molybdenum, and tungsten, it is shown that yield behavior can be represented by a single-valued relation between two dimensionless parameters.

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Preliminary compression of a material as a factor in changing the brittle fracture mechanism for BCC metals

Strength of Materials ◽

10.1007/bf02210369 ◽

1996 ◽

Vol 28 (4) ◽

pp. 251-261 ◽

Cited By ~ 4

Author(s):

B. Z. Margolin ◽

V. A. Shvetsova ◽

A. Ya. Varovin

Keyword(s):

Brittle Fracture ◽

Fracture Mechanism ◽

Bcc Metals

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Field-Ion Microscopy of BCC Metals: A Study of Image Differences and Topographical Variations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071016 ◽

1973 ◽

Vol 31 ◽

pp. 114-115

Author(s):

O. T. Inal ◽

L. E. Murr

Keyword(s):

Liquid Nitrogen ◽

Liquid Nitrogen Temperature ◽

Surface Atom ◽

Image Brightness ◽

Field Ion Microscopy ◽

Topographic Features ◽

Bcc Metals ◽

Electron Orbital ◽

Ion Microscopy ◽

Field Ion Microscope

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.

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Solid Solution Effects and Deformation Micros trueture of Shock-Loaded Iron Manganese Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069090 ◽

1970 ◽

Vol 28 ◽

pp. 420-421

Author(s):

A. Christou ◽

J. V. Foltz ◽

N. Brown

Keyword(s):

Solid Solution ◽

Shock Loading ◽

High Strain ◽

Local Stress ◽

Strain Rates ◽

Local Stress Concentration ◽

Bcc Metals ◽

Manganese Alloys ◽

Iron Manganese ◽

Transmission Microscope

In general, all BCC transition metals have been observed to twin under appropriate conditions. At the present time various experimental reports of solid solution effects on BCC metals have been made. Indications are that solid solution effects are important in the formation of twins. The formation of twins in metals and alloys may be explained in terms of dislocation mechanisms. It has been suggested that twins are nucleated by the achievement of local stress-concentration of the order of 15 to 45 times the applied stress. Prietner and Leslie have found that twins in BCC metals are nucleated at intersections of (110) and (112) or (112) and (112) type of planes.In this paper, observations are reported of a transmission microscope study of the iron manganese series under conditions in which twins both were and were not formed. High strain rates produced by shock loading provided the appropriate deformation conditions. The workhardening mechanisms of one alloy (Fe - 7.37 wt% Mn) were studied in detail.

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