ATOMIC-STRUCTURE AND ENERGY OF SIGMA = 5 TILT BOUNDARIES IN GOLD

The atomic structure of 2 = 5(θ = 36.9 deg) [001] tilt boundaries in gold has been investigated by high-resolution electron microscopy (HREM). Image simulations and experimental conditions for observing grain boundary atomic structure in gold are presented. Two preferred orientations corresponding to symmetric {310} and asymmetric {430}//{100} inclinations have been observed frequently. A single symmetric {210} inclination has also been observed. The atomic structures of these three boundaries are presented. An average ratio of grain boundary to surface energy, γgb/γs, of 0.62 has been measured at 200 °C. Unique atomic structures are observed for {310}, {430}//{100}, and {210} inclinations, and multiplicities in atomic structures have not been detected. Interfacial volume expansion of these interfaces is presented and compared to computational models. © 1990 The Metallurgical of Society of AIME.