Article: Carson, R; Obstalecki, M; Miller, M; Dawson, P; “Characterizing Heterogeneous Intragranular Deformations in Polycrystalline Solids using Diffraction-Based and Mechanics-Based Metrics”, Modelling and Simulation in Materials Science and Engineering, 25 (5)
Abstract: Deformations within and among crystals have been observed to be heterogeneous for most structural alloys whether the alloys are subjected to monotonic or cyclic loading. Over a material’s loading history, these intragrain deformations influence how failure mechanisms activate. A series of finite element simulations were conducted for a completely reversed loading cycle applied to a precipitation hardened copper alloy. The simulations were conducted using different hardening assumptions within a single crystal, elasto-viscoplastic constitutive model. The results were used to develop several intragrain heterogeneity metrics applicable to both measured and computed data. The computed metrics are shown to correlate strongly with the corresponding values derived from x-ray diffraction experiments. The intragrain heterogeneity metrics provide an effective tool to quantitatively measure and compare the influence of different constitutive models under the same loading conditions. This is demonstrated for the differences in deformation heterogeneity between isotropic and anisotropic hardening assumptions under cyclic loading.
Funding Acknowledgement: US Department of Energy, Materials Sciences and Engineering Division, Office of Basic Energy Sciences [DE-SC0004913]; DOE Office of Science [DE-AC02-06CH11357]
Funding Text: Support was provided by the US Department of Energy, Materials Sciences and Engineering Division, Office of Basic Energy Sciences under Grant No. DE-SC0004913 (Dr John Vetrano, Program Manager). The diffraction experiments were conducted at beamline 1-ID-C of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Rocketdyne provided the OMC copper used in these experiments. Dr Jim Williams is acknowledged for the metallurgical expertise he provided to the project and for securing the OMC material.