Mobility of low-angle grain boundaries in pure metals

Abstract

The mobility of low-angle grain boundaries in pure metals is reviewed and several theoretical treatments are provided. The approach that provides the best agreement with the available experimental data is one in which the mobility is controlled by vacancy diffusion through the bulk to (and from) the dislocations that comprise the boundary that are bowing out between pinning points. The pinning points are presumed to be extrinsic dislocations swept into the boundaries or grown in during the prior processing of the material. This approach yields a mobility that is constant with respect to misorientation angle, up to the transition to the high-angle regime. For small misorientations of the order 1°, however, the mobility appears to increase with decreasing misorientation angle.

Keywords:

• low-angle grain boundary
• dislocation interaction
• grain boundary mobility

Acknowledgements

ADR acknowledges the partial support of the MRSEC program of the National Science Foundation (Award Number DMR-0520425) and the hospitality of the Institute für Metallkunde und Metallphysik during a sabbatical period at the RWTH, Aachen in 2003. DJS gratefully acknowledges the support of the US Department of Energy (Grant No. DE-FG02-99ER45797). ADR and DJS also acknowledge the support of the Computational Materials Science Network, a program of the Office of Science, US Department of Energy. GG and LS gratefully acknowledge financial assistance from the Deutsche Forschungsgemeinschaft (Grant Go 335/10 and Grant Mo 848/7). The cooperation was supported by the Deutsche Forschungsgemeinschaft (DFG Grant 436 RUS 113/714/0-1(R)) and the Russian Foundation of Fundamental Research (Grant DFG-RRF1 03 02 04000). MW gratefully acknowledges financial support from the Deutsche Forschungsgemeinschaft through the Heisenberg program (Grant WI 1917/4).