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51.
The microstructures of an Fe–20Mn–2Si–2Al Twinning-Induced Plasticity (TWIP) steel deformed at different temperature were characterized by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Based on microstructural features revealed at various characteristic temperature regions of deformation, the necessary and sufficient conditions of TWIP effect are proposed. Likewise, the competitive characteristic deformation mechanism occurring in this TWIP steel is presented and discussed qualitatively in terms of phase stability and stacking fault energy of the austenitic matrix. 相似文献
52.
It is shown that the compressive plasticity of a metallic glass, namely Zr52.5Ni14.6Al10Cu17.9Ti5, can be improved by the introduction of two symmetrical notches. The enhanced plasticity may be ascribed to a blocking effect of the propagation of shear bands caused by large stress gradients around the notches. In contrast to ceramic specimens with similar notches, the plasticity enhancement of metallic glass induced by notches can provide a new approach to understanding its unique mechanism of deformation. 相似文献
53.
Solution-treated, peak-aged and overaged samples of the model alloy Al–3?wt.% Cu, obtained by selective heat treatments of the pre-material, have been subjected to high-pressure torsion at room temperature and at 200?°C. The mechanical behaviour of the samples was investigated with torque measurements during deformation and microhardness measurements after deformation. Irrespective of the initial material condition, in the saturation regime a comparable equilibrium microstructure was found consisting of ultrafine aluminium grains stabilized by precipitates formed at grain boundaries. 相似文献
54.
Al–Pb samples containing 1?at.%?Pb were produced by high-energy ball milling and investigated by high-resolution transmission electron microscopy. The Pb inclusions embedded in an Al matrix exhibit a non-faceted, curved morphology. Dislocations have been found to accommodate the misfit of about 22% at the Al–Pb interfaces. Burgers circuits, drawn around these misfit dislocations, exhibit closing failures of the type a0 /4〈211〉. 相似文献
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56.
B.B. Straumal S.G. Protasova A.A. Mazilkin B. Baretzky D. Goll D.V. Gunderov 《Philosophical Magazine Letters》2013,93(10):649-654
Cast Co–5.6 wt% Cu and Co–13.6 wt% Cu alloys were subjected to severe plastic deformation (SPD) by high-pressure torsion (HPT). The HPT treatment drastically decreases the size of the Co grains (from 20 µm to 100 nm) and the Cu precipitates (from 2 µm to 10 nm). As a result, the coercivity H c of both the alloys radically increases. The saturation magnetization, M s, remains almost unchanged. Thus, SPD of the bulk samples opens the way for drastic increase in the coercivity for the Co-based alloys. 相似文献
57.
Nicholas Joll 《International Journal of Philosophical Studies》2013,21(2):233-253
Abstract This paper provides a criticial interpretation of the theme, point, and methodological status of Adorno’s so‐called negative dialectic. The theme at issue, ‘non‐identity’, comes in several varieties; and the point of Adorno’s dialectic, namely reconciliation, is multifaceted. Exploration of those topics shows that negative dialectic seques into substantive doctrines, including a version of transcendentalism and a claim about deformation. The peculiar methodological status of negative dialectic explains that adumbration. In the appraisive register, my principal contentions include these: Adorno’s transcendentalism makes some sense of the aforementioned deformation claim; and negative dialectic qua method avoids mystery and metaphysical excess. 相似文献
58.
Beyond the heritability of life satisfaction – The roles of personality and twin-specific influences
Elisabeth Hahn Wendy Johnson Frank M. Spinath 《Journal of research in personality》2013,47(6):757-767
In a behavior genetic design, we investigated individual differences in life satisfaction and its relation to personality with respect to both internal and external influences. We questioned the absence of shared environment and examined the specific contribution of additive and non-additive genetic influences. We also tested for twin-specific environmental influences in a total sample of 1308 dyads including identical and fraternal twins, siblings, mother–child and grandparent–child pairs. The results showed substantial shared environmental influences on life satisfaction that varied between twins and non-twins, supporting twin-specific environmental influences. Additive and non-additive genetic influences on life satisfaction were completely shared with personality. The remaining variance could be explained by unique non-shared environmental influences for life satisfaction independent of personality. 相似文献
59.
We develop a model for recently observed 〈c + a〉 dislocation transmission across nano-spaced parallel basal stacking faults in hexagonal close-packed (HCP) Mg microcrystalline grains. The model theoretically predicts nanospace-dependent yield strength that is in good agreement with experimental data. Additionally, it theoretically predicts activation volume and strain rate sensitivity. 相似文献
60.
We present the results on the modelling of structural changes in pentagonal small particles (PSPs) during their growth. We prove that after a certain critical size it becomes energetically favourable for a PSP to form a subsurface layer free of twin boundaries (TBs), which are only typical structural elements for smaller size PSPs. In this layer, the low-angle dislocation boundaries (DBs) are formed. Our calculations of the energy stored in the transformed PSP are based on the disclination model of a PSP, in which the TB junctions, as well as TB–DB junctions are treated as wedge disclinations. 相似文献