An X-ray interface continuous tracking device was developed which was capable of monitoring grain boundary motion. It was found that the grain boundary velocity changed in proportion to the driving force. The orientation dependence of the mobility not only affected the activation enthalpy for grain boundary motion, but also the pre-exponential mobility factor. This caused the exact  = 7 boundary to move fastest at low temperatures. However, the 40.5 <111> boundary was most mobile at high temperatures. It was confirmed that impurities reduced the grain boundary mobility, but the mobility could also be enhanced by adding small amounts of Ga to pure Al.

G.Gottstein, U.Czubayko, D.A.Molodov, L.S.Shvindlerman, W.Wunderlich: Materials Science Forum, 1996, 204-206, 99-108