Accession Number:

AD0733303

Title:

Torques on Singular Surfaces.

Descriptive Note:

Technical rept.,

Corporate Author:

ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MASS

Report Date:

1971-07-01

Pagination or Media Count:

19.0

Abstract:

The concepts involved in expressing the surface torques on singular surfaces which correspond to cusps in the gamma-plot of surface energy versus surface inclination are clarified and extended. For equilibrium morphologies formed by faceting, it is demonstrated that the torque displayed by a singular surface is a property of the particular state of interfacial equilibrium in which the torque is measured. The magnitude of the effective torque will in general lie between the limiting values of the angular derivatives at the cusp corresponding to the singular surface on the appropriate two-dimensional section through the gamma-plot the gamma sub 2-plot. An extension of a construction due to Gjostein is presented by which the effective torques may be obtained for equilibrium morphologies resulting from linear faceting when the shape of the gamma sub 2-plot is known. This is illustrated with several examples involving singular surfaces, including that of faceted 10-10 grain boundaries in zinc. Author

Subject Categories:

  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE