GRAIN-BOUNDARY ENERGY AND THE ROTATION AND TRANSLATION OF CU SPHERES DURING SINTERING ONTO A SUBSTRATE

A technique for measuring the rotation and lateral movement of small Cu spheres during sintering on to single crystal substrates is described. The rotation of the spheres about each of three perpendicular axes is derived from selected area channelling patterns observed in a scanning electronmicroscope (SEM). The Shewmon sphere rotation mechanism is re-examined and shown to involve a rolling translation. The measured sphere translations are often larger than expected from the rotation and this is ascribed to grain boundary sliding during sintering. Rotation about the axis normal to the boundary is much faster than the Shewmon rotation, confirming the Pond-Smith rotation mechanism. The possibilities of using single sphere rotation trajectories and rotation velocities to evaluate the orientation dependence of grain boundary energy are discussed. © 1979.