ISSN:
1460-2695
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract— In order to study the cyclic stress-strain behaviour under variable amplitude loading in terms of dislocation glide character and microstructure, various metals and alloys were cyclically loaded in single-step tests and in an incremental step test (IST). The cyclic stress-strain curves (CSS curves) which correspond to the different loading conditions were compared and the shapes of the hysteresis loops were analysed with respect to Masing or non-Masing behaviour.As expected, cyclic loading with constant amplitude leads to the formation of a characteristic dislocation arrangement that depends on the amplitude applied. The amplitude-related microstructure corresponds to the observation that Masing behaviour was not found in single-step tests. However, in the IST a state of saturation, or at least approximate saturation, is attained after some or many loading blocks. In the case of single-phase polycrystalline materials, wavy slip behaviour was found to be a prerequisite for the fulfilment of Masing behaviour. Then, the CSS curve, obtained by means of IST, intersects that of the single-step tests at an intermediate amplitude. Planar-slip materials show very similar CSS curves in spite of considerable differences in the dislocation arrangements for different testing modes. The behaviour of particle-hardened alloys depends very strongly on the relative effectiveness of the precipitates as obstacles for dislocation motion and can be understood analogously to single-phase materials on the basis of the resulting dislocation glide character.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1460-2695.1996.tb00971.x
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