Charles J. McMahon

Charles J. McMahon, Jr.

Professor Emeritus
Materials Science and Engineering

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Research Expertise: Mechanical Behavior | Metals | Surfaces & Interfaces

High-strength materials can undergo failure by decohesion, usually along grain boundaries, if a high tensile stress is applied while a surface-adsorbed low-melting-point element is present on the surface at a temperature where the surface element is mobile. A theory has been developed to model the diffusion-controlled crack-growth, and it is being tested with a variety of materials, both polycrystals and bicrystals, including alloy steels, copper-based and nickel-based alloys, and an iron-silicon alloy. The surface elements originate from either a vapor or a surface coating (solid or liquid) or from solid solution in the alloy being studied. This phenomenon is actually widespread in engineering materials, but the mechanism is not widely appreciated.

Education:
Sc. D. Physical Metallurgy 1963 - Massachusetts Institute of Technology
B.S. Metallurgical Engineering 1955 - University of Pennsylvania

Recent Publications

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