Crack-like grain-boundary diffusion wedges in thin metal films
- Stanford Univ., CA (United States)
- Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering
- Max-Planck-Inst. fuer Metallforschung, Stuttgart (Germany)
Constrained grain-boundary diffusion in polycrystalline thin metal films on substrates is studied as a strongly coupled elasticity and grain-boundary diffusion problem in which no sliding and no diffusion are allowed at the film/substrate interface. Surface diffusion and grain-boundary grooving are neglected in the present analysis. The authors show that such a diffusion process leads to the formation of crack-like grain-boundary wedges which cause the normal traction along the grain boundary to decay exponentially with time. A rigorous mathematical analysis is performed to derive and calculate the transient solutions for diffusion along a single grain boundary and along a periodic array of grain boundaries. An approximate closed-form solution is also given as a simple description of constrained grain-boundary diffusion. A most remarkable feature of the solution is that the diffusion wedges induce crack-like singular stress concentrations which could also enhance dislocation plasticity processes in a metal film.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States); USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG03-89ER45387
- OSTI ID:
- 684389
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 10 Vol. 47; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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