Simulated small-angle scattering patterns for a plastically deformed model composite material

Abstract

Simulated small-angle scattering patterns for a plastically deformed model composite material Shenoy, V.B.; Cleveringa, H.H.M.; Phillips, R.; Giessen, E. van der; Needleman, A. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Abstract. The small-angle scattering patterns predicted by discrete dislocation plasticity versus local and non-local continuum plasticity theory are compared in a model problem. The problem considered is a two-dimensional model composite with elastic reinforcements in a crystalline matrix subject to macroscopic shear. Only single slip is permitted in the matrix material. Emphasis is on the relationship between characteristics of the scattering patterns and the dislocation structures that can develop as a function of the composite morphology. The computed small-angle scattering patterns clearly distinguish between the different dislocation structures that arise for different composite morphologies. Many features of the small-angle scattering patterns are also reproduced by continuum slip plasticity theory, although the local features due to the discreteness of the individual dislocations are not. The non-local hardening description that gives the best fit with the overall stress-strain response is found to also give the best agreement between the non-local continuum and the discrete dislocation scattering patterns.

Formation of (Fe,Cr) carbides and dislocation structures in low-chromium steel studiedin situusing synchrotron radiation

“…Fig. 10(b) clearly illustrates the presence of the dislocation Bragg peaks, in other words the spottiness of the pattern, which was also previously observed by Shenoy et al (2000). This pattern indicates the presence of perpendicular dislocation walls in the metal sample.…”

“…Scattering from dislocations and various types of dislocation wall was investigated by Thomson et al (1999), van der Elsken et al (1996), Long & Levine (2005) and Shenoy et al (2000). The two-dimensional SAXS pattern from the dislocation wall model described in x3.2 was simulated and compared with the SAXS and 3DXRD patterns recorded during rotation around the z lab axis: (a) at the angle at which the streak and the spot start to appear, (b) at the angle at which the intensities of the streak and the spot are at their maximum, and (c) at the angle at which the streak and the spot start to disappear.…”

“…More recently, the dislocation wall model was tested using in situ ultra-small-angle X-ray scattering (USAXS) from dislocation structures from Al samples (Long & Levine, 2005). The dislocation wall theory has also been applied for computing scattering patterns from deformed composite materials (Shenoy et al, 2000). In the present study, in situ SAXS measurements are performed to investigate the evolution of the size distribution of (Fe,Cr) carbides in steel during heat treatment.…”

Micropolar crystal plasticity simulation of particle strengthening

“…Experimental, theoretical and computational studies indicate that the dislocation-particle interactions are size-dependent [1], thus, classical continuum plasticity models are ill-equipped for addressing this aspect of the problem. For this reason, a number of researchers have studied the deformation behavior of two-phase composites with particle strengthening using nonlocal modeling approaches including Shenoy et al [2], Needleman and Van der Giessen [3], Forest and Sedlacek [4], Chang et al [5], Cordero et al [6], Schwarz et al [7], Yassar et al [8], and Taupin et al [9,10].…”

Simulation of X-ray diffraction-line broadening due to dislocations in a model composite material

“…Subsequently, XRD line profiles of the model composite material are calculated and interpreted. A similar procedure for small angle scattering has been conducted in [8].…”