| Abstract |
| A nanoindentation model for analyzing thin-film stress has been developed by considering stress interaction and relaxation concepts. It was applied to the stress characterization of diamond-like carbon and Au thin films in previous studies(Y.-H. Lee et al., J. Kor. Inst. Met. & Mater., 39 (2001) p. 1101 and Y.-H. Lee et al., J. Kor. Inst. Met. & Mater., 40 (2002) p. 744). However, the validity of the proposed model cannot be directly confirmed by the thin film testing with various affecting factors. Nanoindentation on thin film can be affected by additive deformation of free-standing film, surface roughness and microstructural inhomogeneity. Therefore, we tried to verify the proposed model experimentally through the nanoindentation tests on an artificially stressed monolithic material instead of thin film. An electropolished (100) tungsten single crystal, which is free from the microstructural inhomogeneity, was used for a nanoindentation specimen. Nanoindentation curves obtained from the stress-free and the artificially stressed states using specially designed jigs were compared and analyzed based on the proposed stressanalysis model. The analyzed stress from the proposed model was consistent with the artificially applied stress measured from the strain gage attached on the specimen surface. |
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| Key Words |
| Residual stress-analyzing model, Nanoindentation, Tungsten single crystal, Artificially applied stress |
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