BEER - The Beamline for European Materials Engineering Research at the ESS

The Beamline for European Materials Engineering Research (BEER) will be built at the European Spallation Source (ESS). The diffractometer utilizes the high brilliance of the long-pulse neutron source and offers high instrument flexibility. It includes a novel chopper technique that extracts several short pulses out of the long pulse, leading to substantial intensity gain of up to an order of magnitude compared to pulse shaping methods for materials with high crystal symmetry. This intensity gain is achieved without compromising resolution. Materials of lower crystal symmetry or multi-phase materials will be investigated by additional pulse shaping methods. The different chopper set-ups and advanced beam extracting techniques offer an extremely broad intensity/resolution range. Furthermore, BEER offers an option of simultaneous SANS or imaging measurements without compromising diffraction investigations. This flexibility opens up new possibilities for in-situ experiments studying materials processing and performance under operation conditions. To fulfil this task, advanced sample environments, dedicated to thermo-mechanical processing, are foreseen

Crystallographic phase composition and structural analysis of Ti-Ni-Fe shape memory alloy by synchrotron diffraction

Abstract:The preferred crystallographic orientation (i.e. texture) and the non-transformed austenite can cause serious systematic errors in the structural study of the R-phase in 50.75at.%Ti-47.75at.%Ni-1.50at.%Fe (hereafter referred to as Ti-Ni-Fe ternary) shape memory alloy. The crystal structure refinement of R-phase synchrotron high resolution powder diffraction (SRD) data using Rietveld refinement with generalized spherical harmonic (GSH) description for preferred orientation correction showed that the sample consists of minor cubic phase and the space group was 3 P [1]. The objective of the present paper is to study the crystallographic phase composition and crystal structure refinement of SRD data of trigonal R-phase martensite and monoclinic (B19′) martensite in Ti-Ni-Fe ternary alloy during thermal cycling using the GSH description. Introduction The trigonal R-phase martensite transformation in Ti-Ni-Fe ternary shape memory alloy (SMA) has been widely used in the fundamental research because of the shape memory effect (or superelasticity). Also, the R-phase transformation has small thermal hysteresis which is very useful for actuators applications Subsequently, the crystal structure of the rod shaped Ti-Ni-Fe alloy was non-destructively determined by Sitepu [1] using SRD data. The results obtained from Rietveld refinement with the GSH description (i) for texture in SRD data sets of R-phase the reasonable crystal structure parameters was obtained when applying correction to intensities using the GSH description, (ii) the weight percentage of the non-transformed austenite was approximately 3%, an

Simulation of Deformation Texture Evolution During Multi Axial Forging of Interstitial Free Steel

Bulk texture measurement of multi-axial forged body center cubic interstitial free steel performed in this study using x-ray and neutron diffraction indicated the presence of a strong {101}aOE (c) 111 > single texture component. Viscoplastic self-consistent simulations could successfully predict the formation of this texture component by incorporating the complicated strain path followed during this process and assuming the activity of {101}aOE (c) 111 > slip system. In addition, a first-order estimate of mechanical properties in terms of highly anisotropic yield locus and Lankford parameter was also obtained from the simulations

Textures in pure shear deformed rock salt

Texture formation in pure shear deformed rock salt has been studied by neutron diffraction. The textures developed are comparable to those of rolled face-centered cubic metals with high stacking fault energy. At room temperature the texture consists of a strong S and copper and a weaker brass component. It is replaced by static and/or dynamic recrystallization by a strong cube and a subordinate Goss component. Comparison of the experimental textures with simulations based on different models shows that the low temperature high strain deformation texture can be qualitatively well explained by the Taylor model using slip on {110}?110?, {100}?110? and {111}?110? systems with equal critical resolved shear stresses. Relaxation with increasing temperature introduces the cube and Goss component, which may represent the nuclei for recrystallization. The study shows that texturesimulations on salt without considering recrystallization lead to misleading conclusions

In-situ study of tensile deformation behaviour of medium Mn TWIP/TRIP steel using synchrotron radiation

This investigation proposes a pathway for generating optimum microstructure for a medium Mn containingtwinning-induced plasticity/transformation-induced plasticity (TWIP/TRIP) steels. The steel contains a twophasemicrostructure consisting of austenite and ferrite phase arranged in a lamellar fashion. The microstructurewas developed following a specially designed thermo-mechanical processing schedule that involvedquenching and partitioning. The feedback for the design of thermo-mechanical processing was obtained bycarrying out in-situ deformation in high energy synchrotron radiation under tensile loading. Diffraction patternswere analysed for estimating the retained austenite phase fraction and other aspects of microstructural evolution.X-ray line profile analysis was performed to determine crystallite size, dislocation density, and twin density atindividual stages of deformation. In the early stages, deformation occurs by dislocation slip in both phases, whilein the later stages, deformation in the austenite phase occurs via twinning and martensitic transformation, and inthe ferrite phase by dislocation slip. Strain hardening behaviour has been analysed and correlated with microstructuralparameters