Issues »  Volume 48, Issue 7

The Role of Plasticity in the Fracture of Metals and Alloys

Yu. Ya. Meshkov, H. P. Zimina, Yu. O. Polushkin

G. V. Kurdyumov Institute for Metal Physics, N.A.S. of Ukraine, 36 Academician Vernadsky Blvd., UA-03142 Kyiv, Ukraine

Received: 27.05.2025; final version - 25.08.2026. Download: PDF

In the review paper, the mechanical property of plasticity is considered from the standpoint of its effect on the brittleness of metallic materials due to influence on the mechanical stress–strain state (SSS) of a metal under a force load: the appearance of plasticity limits the elastic form of the SSS at the yield point of a metal σ0.2 and generates the elastic–plastic form of the SSS within the stress range from σ0.2 to SK (the true fracture stress of a sample in ‘neck’). Stress interval ΔS = SK - σ0.2 is a mechanical-stability margin (MSM) of the stress state of a metal with a numerical characteristic of MSM in the form of a coefficient Br = SK/σ0.2 (break resistance), which provides the ductile metal with a protection margin against brittle fracture at Br > 1. Plasticity creates within the metal a means to protect against rapid destruction (brittleness). The break-resistance coefficient Br is a parameter for quantitative measurement of the metal ability to resist fracture of a metal in general, including under the action of stress raisers (SR) (notches, cracks, etc.). This paper presents the results of the analysis of experiments from literary sources on the role of break-resistance coefficient Br in the processes of fracture of structural steels for specimens with stress raisers at both room and low test temperatures.

Key words: strength, strength stability, break resistance, overstrain, overstrain concentrator, brittleness, critical parameter of brittleness, subcritical and supercritical fracture, protective resource of plasticity.

URL: https://mfint.imp.kiev.ua/en/abstract/v48/i07/0757.html

DOI: https://doi.org/10.15407/mfint.48.07.0757

PACS: 46.50.+a, 62.20.fq, 62.20.mj, 62.20.mm, 62.20.mt, 81.40.Lm, 81.40.Np

Citation: Yu. Ya. Meshkov, H. P. Zimina, and Yu. O. Polushkin, The Role of Plasticity in the Fracture of Metals and Alloys, Metallofiz. Noveishie Tekhnol., 48, No. 7: 757–773 (2026) (in Ukrainian)

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