Understanding the micromechanical behavior of polycrystalline material is pivotal for regulating its mechanical performance and widening its application. Taking advantage of its non-destructive nature, the neutron diffraction technique has been widely applied to investigate the micromechanical behaviors, usually at the resolution of grains sharing the same diffraction plane. This work employs a newly developed technic of the texture-component-dependent (TCD) in-situ neutron diffraction method to obtain the full strain/stress tensor of a textured CuZnPb alloy at the resolution of individual crystallographic orientation. The variation of the internal stresses and lattice strains over the grains that share the same diffraction plane has been successfully captured by the TCD method. According to the results of in situ neutron diffraction, Copper ({-1-1-2}<-1-11>) possesses the highest lattice stress while Cube ({010}<100>) and Goss ({110}<001>) bear the lowest stress of 370 MPa. In parallel, the micromechanical response of the texture components is modeled by the elastic visco-plastic self-consistent (EVPSC) model. The simulated results are in reasonable agreement with the corresponding experiments in loading direction, while the lateral stress exhibits some deviation. By crystal plasticity finite element modeling, the deviation is related to the neighbor grain which affect more significantly the lateral stress than the material parameters. The full tensor of stress within the individual crystallographic orientation measured by TCD method gives more insight into the crystal plasticity modeling.

This paper presents an experimental investigation of irradiation-induced evolutions in three different oxide dispersion strengthening (ODS) alloys. High-dose, dual beam Ni–He ion irradiations are carried out up to 700 °C. The significant dose-dependent changes in the ODS particle size and number density are documented and interpreted in terms of specific point defect transport mechanisms, from small angle neutron scattering, TEM, and pulsed low-energy positron system measurements combined. The corresponding micro-mechanical changes in the alloys are evaluated based on the indentation response, which is, in turn, interpreted in terms of related, sub-grain plasticity mechanisms. The room temperature tests (without dwell time) reveal that the microscale work-hardening rate increases with decreasing the particle number density and pronounced strain localization effect. The elevated temperature tests (up to 600 °C, with dwell time) show that the indentation creep compliance is mostly temperature-independent after irradiation up to 25 dpa at Tirr = 500 °C and markedly temperature-dependent, after irradiation beyond 40 dpa at Tirr = 600 °C. This effect is ascribed to particular creep mechanisms associated with indent-induced plasticity, i.e., high stress and high dislocation density conditions.

The microstructure and texture of 7075-T6 FSW weld with optimal parameters are investigated using optical microscopy, electron back scatter diffraction and neutron diffraction. The mechanical properties are characterized through microhardness, nanoindentation and ultrasonic tests. The friction stir welding is performed at a nominal rotational speed of 1400 rpm and a traverse speed of 60 mm/min. The nugget zone contained fine, equiaxed and fully recrystallized grains. The texture of the base material mainly consisted of Cube and rotated Goss components. However, in the nugget zone, the dominant texture components were B and $${\bar {\text{B}}}$$ among common shear orientations. Elastic modulus was measured by ultrasonic and nanoindentation methods. The ultrasonic method being nondestructive, easy, inexpensive and fast. It is found that a little increase of Young modulus is observed in nugget zone compared to base metal.

In this study we present an analysis of the evolution of the texture of a mild steel welding rod from the initial state to the welded state. And thus show the effect of drawing on the texture of the welded metal. The analysis of the initial state reveals the presence of a slight texture of the ferritic phase at the periphery. Several hypotheses are emitted but the main cause of the presence of the fiber <110> has not yet been identified. The first deformation leads to the development of the fiber <110> over the entire section of the drawn wire. At this deformation level, the pearlitic phase does not appear to undergo any apparent deformation and the quantitative analysis shows a homogeneous distribution of the texture between the core and the periphery of the wire. After the second deformation, the perlite undergoes a very visible deformation under the light microscope and the fiber <110> becomes more intense in the core than on the periphery of the wire. The examination of the texture of the welded state exhibits another texture composed of three <100>, <110> and <111> fibers whose ratios vary according to the observed angle. The chemical analysis reveals presence of elements of coating of a rod in a matrix of welded metal. It has been found that the drawn state of the rod and the manner in which welding is performed influence the texture of the deposited metal, but their separate effects need to be more inspected.

The precipitation of nano-sized Cr clusters was investigated in a commercial Cu-1Cr-0.1Zr(wt.%) alloy processed by equal-channel angular pressing and subsequent aging at 550 • C for 4 h using Small-Angle Neutron Scattering (SANS) measurements and High-Angle Annular Dark-Field-Scanning Transmission Electron Microscopy (HAADF-STEM).The size and volume fraction of the nano-sized Cr clusters were estimated using both techniques.The parameter values assessed by SANS (d ∼ 3.2 nm, Fv ∼ 1.1 %) agreed reasonably with those by HAADF-STEM (d ∼ 2.5 nm, Fv ∼ 2.3 %).In addition to the nano-sized Cr clusters, HAADF--STEM indicated the presence of rare cuboid and spheroid sub-micronic Cr particles measuring approximately 380-620 nm in mean size.Both techniques did not evidence the presence of intermetallic CuxZry phases within the aging conditions.

alpha' precipitation in a Fe-19 at.%Cr alloy aged at 500 degrees C up to 2008 h has been characterized by both APT and SANS. This paper shows that when using an appropriate method for SANS data treatment, both APT and SANS yield consistent results regarding not only volume fraction and size but also alpha and alpha' composition. Good agreement is achieved when alpha' particles are considered as magnetic scattering features at the early stage of the kinetics.

Texture development of particle-reinforced metal matrix materials (P-MMCs) has not been understood well, especially the effects of second-phase particles during the deformation. In this work, we have investigated the texture evolution of TiB2/Al composites during cold rolling by Neutron Diffraction and EBSD analysis. Two forms of TiB2 particles influenced the texture evolution in different ways. The particle-clusters aggregated along grain boundaries led to a reduction of texture volume fraction; recrystallization nuclei with weak texture appeared around these particle-clusters. Small non-shearable TiB2 particles dispersed inside Al matrix contributed to strong Copper texture component at high strains; the individual particles rotated together with Al matrix during the deformation. These revealed effects of particles on the texture development in TiB2/Al composites provide a reference for the texture control of P-MMCs.

The present study shows the influence of severe plastic deformation on highly stable Y-Ti-O nano-oxides present in ferritic ODS alloys used for nuclear applications. An innovative strain path implying alternated compressions was used to deform the material to an equivalent plastic strain of 13. Energy Filtered Transmission Electron Microscopy and Small Angle Neutron Scattering revealed the strain-induced dissolution of the Y-Ti-O nano-oxides. It appears to be the first time that dissolution of such particles is clearly observed after deformation. Annealing the material enables to re-precipitate the nano-oxides. These results show a strong analogy with the mechanical alloying of ODS powder.

We analyze measurements of dislocation densities carried out independently by several teams using three different methods on orientation maps obtained by Electron Back Scattered Diffraction on commercially pure tantalum samples in three different microstructural states. The characteristic aspects of these three methods: the Kernel average method, the Dillamore method and the determination of the lattice curvature-induced Nye’s tensor component fields are reviewed and their results are compared. One of the main features of the uncovered dislocation density distributions is their strong heterogeneity over the analyzed samples. Fluctuations in the dislocation densities, amounting to several times their base level and scaling as power-laws of their spatial frequency are observed along grain boundaries, and to a lesser degree along sub-grain boundaries. As a result of such scale invariance, defining an average dislocation density over a representative volume element is hardly possible, which leads to questioning the pertinence of such a notion. Field methods allowing to map the dislocation density distributions over the samples therefore appear to be mandatory.

In this study, we will examine the phenomenon of precipitation that appears in the aluminum alloy AGS wires. Since the studied wires are drawn, we will try to see also the effect of the deformation on this phenomenon.The precipitation was believed to be the main cause of hardening in the AGS 6101 wire rod. The hardening appears in this wire, after a period of storage, and causes the elevation of its hardness from 7% to 18% and its maximum tensile load from 4% to more than 22% depending on storage times.Microstructural analysis of wire rod and drawn wires shows the existence of precipitates in the microstructures. Optical microscopy reveals the presence of two precipitates of different sizes and colors: whitish and dark gray. Under the scanning electron microscope, two types of precipitates appear: light gray and gray, ranging from 3 to 12 mu m.X-ray diffraction analysis did not reveal the presence of precipitates, observed by light microscopy and scanning electron microscopy. The EDS analysis allowed the measurement of the chemical composition of the light gray precipitates that were identified as the Mg2Si intermetallic compound.Note that the effect of deformation on precipitation in AGS 6101 alloy was not clearly found in this study. Because the wires used in this study were part of the same batch as the wire rod, in part. On the other part, the exploitation of background signal with XRD software does not seem very convincing.

The microstructure and texture of an Al1050/AZ31/Al1050 laminated composite fabricated by accumulative roll bonding at 400 degrees C up to 5 cycles are investigated using Electron BackScatter Diffraction, neutron diffraction, microhardness measurements and tensile tests. EBSD analysis has shown that ARB processing led to micro-structural refinement with equiaxed grain microstructure in AZ31 layers and to the development of elongated grains parallel to the rolling direction in Al 1050 layers. No new phases formed at the bond interface after the first ARB cycle while Mg17Al12 and Mg2Al3 phases appeared after subsequent cycles. During the ARB processing, a typical strong basal (0002) texture is observed in AZ31 layers along with a weak rolling texture showed in Al 1050 layers with a dominant Rotated Cube {001}< 110 > component. The microhardness of Al1050/AZ31/Al1050 laminated composite increased with increasing ARB cycles and almost saturated after five ARB cycles. The yield strength and ultimate strength increased gradually between 1 and 3 ARB cycles due to the strain hardening and grain refinement. They decreased with further increasing of the ARB cycles because of crack and failure of the MgxAly intermetallic compounds which developed during 4th and 5th ARB cycles. The deformation behavior of the laminated composite becomes rather similar to the behavior of AZ31 alloy that underwent a dynamic recrystallization during processing.

The ENICAB company in Biskra uses the cold drawing process on several types of wires rod of different materials and grades. Our study was carried out on an Al-Mg-Si (AA6101) aluminum alloy wire rod, the most used by the ENICAB company in the manufacture of electrical energy transmission cables. The purpose of this work is to understand the evolution of the deformation texture and the stored energy in the grains during cold drawing of wire, as well as the combined influence of deformation and annealing at 400 degrees C during different holding time on recrystallization kinetics and evolution of local and global crystallographic texture. Characterization methods used in this work is: Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Back Scatter Electron Diffraction (EBSD), X-ray diffraction, Neutron diffraction, Vickers microhardness and Chemical analysis by EDS.

Excellent mechanical properties of oxide-dispersion-strengthened (ODS) alloys arise from a high density of Y-Ti nano-oxides finely dispersed in the matrix. Characteristics of this precipitation can strongly be influenced by oxygen contamination during milling. We studied an as-received and annealed (1h 1150°C) oxygen-enriched ferritic ODS alloy by High Resolution Transmission Electron Microscopy. The as-received sample has unknown b.c.c nano-oxides, while the annealed one has orthorhombic nanoparticles. We propose a phase relaxation during the annealing, confirmed by the observation of a particle where both cubic and orthorhombic structures coexist. The influence of oxygen on the particle structure is also discussed.

AA 6101 wire alloy has been used in the electric transmission lines in company of the cable industries of Biskra (Algeria) for several years. In this work, the AA 6101 alloy was subjected to recrystallization annealing treatment at 400 degrees C and holding for 30 min, to see the effects of this treatment on the mechanical and electrical properties of drawn Al-Mg-Si wire. The recrystallization annealing treatment leads to the microstructural changes of the textured form, which causes the softening of the wire, that is to say an increasing of ductility. On the other hand, this heat treatment accelerates the recrystallization mechanism, accompanied by a softening of the wires and a reduction in the electrical resistivity. Characterization methods used in this work were: Electron back scattered diffraction (EBSD), X-Ray diffraction analysis (XRD), Vickers microhardness, tensile test, measuring electrical resistivity, scanning electron microscope (SEM) and energy diffraction spectrometer (EDS).

The texture evolution of Fe-36%Ni (wt%) alloy processed by accumulative roll-bonding (ARB) up to six cycles was investigated using neutron diffraction. The texture sharpened after the second cycle, showed continuous strength up to six cycles, and was characterized by the typical copper-type texture together with a R-Cube {001}<110> component that appeared after two cycles of ARB processing. The texture obtained by neutron diffraction was compared with that measured by electron backscatter diffraction (EBSD). The neutron diffraction and EBSD texture intensities were substantially similar and exhibited almost the same trends for all texture components. The evolution of the Lankford coefficient R, average Lankford factor (R) over bar, planar anisotropy Delta R, and Young modulus values versus angle to rolling direction calculated from experimental textures of ARBed samples showed that ARB processing increased the plastic anisotropy and Young modulus of the sheet.

The evolution of stored energy associated with Brass {110}<112>, Copper {112}<111>, S {231}<346> and Cube {001}<100> texture components of Fe-36Ni (wt.%) Invar alloy after accumulative roll-bonding (ARB) processing up to 6 cycles was investigated using two methods: Neutron Diffraction peak broadening analysis and Kernel Average Misorientation (KAM) in an electron backscatter diffraction (EBSD). Both methods evidence the stored energy evolution variation as ECopper > ES > EBrass > ECube. The stored energy increases first with strain up to 3 cycles and then decreases and then slightly rises up again between 4 and 6 cycles but with a trend towards stabilization. The overall evolution of the stored energy versus strain was related to the dislocation density and substructure evolution as well as recovery process. The small increase of the stored energy at high deformation levels is due to the production of new dislocations. Comparisons between results obtained with the two methods and with Dillamore approach show that Geometrically Necessary Dislocations (GND) dislocations in the cells/sub-grains walls are the principal contributor to the stored energy of the alloy.

In this study, the evolution of some properties of the wire drawn alloy AGS 6101 will be followed and the effect of a heat treatment at high temperature will be analyzed. OM (optical microscopy) and SEM (scanning electron microscopy) observations showed an homogeneous fibrous microstructure in the longitudinal cross-section. However, the EBSD (electron backscatter diffraction) analysis showed that the distribution of the two main crystallographic fibers <111> and <001> was not homogeneous through the cross-section of the wire. And as the deformation increases, it has been found that the fiber <111> tended to intensify at the wire core and the fiber <001> was distributed at its periphery. In our similar studies on wire drawn copper and steel, similarities in certain behaviors like hardening, recrystallization, have been found, but this phenomenon has not been observed yet. We have also found that the center of the wire stored less energy than the periphery during drawing. A heat treatment at high temperature (400 degrees C during various holding times) for this alloy, which leads to recrystallization, never modified the texture established by drawing and the two fibers <111> and <001> remain predominant. More importantly, treatments beyond 20 minutes led to heterogeneity in recrystallized grain size between the core and the periphery of the wires due to the initial difference in terms of stored energy through the wire section.

Two grades of Fe-Cr-Ni-Al-Ti-Mo maraging steels, with a different titanium content, were investigated. Particular attention was given to the correlation between the precipitated phases and the yield strength. Synchrotron X-ray diffraction, small-angle neutron scattering and atom probe experiments were performed to determine the crystal structure, shape, size distribution, chemical composition, particle number density and volume fraction of precipitates. Both alloys show a strong increase in strength after an aging treatment, which is attributed to the co-precipitation of two different intermetallic phases. Strengthening by a single precipitation of β-Ni (Al,Ti) particles induces a saturation of yield strength around 1600 MPa above a volume fraction of 6 %. The improvement of yield strength is then obtained by introducing a nanoscale co-precipitation of η-Ni3(Ti,Al) phase.