A stereoscopic method for dihedral angle measurement

Abstract

A new method is presented for the measurement of equilibrium dihedral angles in intergranular inclusions, and illustrated with pure copper containing 1 wt% lead. The method is based on the selective dissolution of inclusions visible along a polished metallographic section. Scanning electron microscopy stereo image pairs are then taken and processed so as to enable a three-dimensional digital reconstruction of the inclusion/matrix interface along each inclusion. Spherical caps describing the Cu/Pb interface over non-facetted orientations are then fitted to the measured digital inclusion envelope reconstructions. Knowing the center and radius of these spheres, the true dihedral angle of each specific inclusion can then be deduced with good precision.It is found that the true dihedral angle in the Cu/Pb alloy is not a unique function of temperature, reflecting the (known) anisotropy of high-angle grain boundary energy in copper. C 2005 Springer Science + Business Media, Inc.

The effect of ductility minimum temperature in CuNi25 alloy

“…The single-phase cupronickel alloy seems to be an ideal material to investigations on DMT effect. Conducted on this material investigations [3,4,[19][20][21], they confirm occurrence this phenomena. In work [22] carried out on uniaxial grips experiment at the CuNi alloys has shown the influence of material structure on course of the plastic deformation process in wide range of raising temperatures.…”

Intermediate temperature embrittlement of copper alloys

“…355 ) and (iv) a recent three-dimensional image analysis method developed for lead inclusions in copper (Refs. 129,356 ). The last three methods differ from the first in that they yield individual, rather than average, dihedral angle values.…”

Influence of the grain boundary character on the temperature of transition to complete wetting in the Cu–In system

“…The correct h value appears only in the section containing the common axis of both spherical solid/liquid interfaces. It can be measured either using transmission electron microscopy [12] or by careful three-dimensional analysis of the droplet shape [21,22]. If such methods are not practical due to the large numbers of boundaries to be characterised, then the wetting state is instead evaluated by analysing the appearance of the wetting layers of the second phase and categorising them as either completely, incompletely or not Fig.…”