bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructural evolution during recovery of deformed aluminium—Effect of deformation strain
Authors: Yu Tianbo 
Published: August 2022

Abstract
Recovery takes place during annealing of a deformed metal, releasing some of the stored energy. Many recovery mechanisms have been proposed in the literature and these mechanisms strongly depend on the deformation microstructure. In this work, recent progress in the study of recovery in aluminium is reviewed. In lightly deformed aluminium, subgrain growth (through boundary migration and coalescence) is found to be an important recovery mechanism, whereas in heavily deformed samples, uniform coarsening through Y-junction motion is found to be the dominant recovery mechanism. The kinetics of recovery follows a universal coarsening model for aluminium deformed to both low and high strains, in which the apparent activation energy increases in the course of recovery. Furthermore, a new definition of recovery is suggested to be compatible with observations at both low and high strains.
Microstructure and chemical characterization of Linear Friction Welded aerospace materials with focus on dissimilar joints
Authors: Boyat X , Ballat-Durand D , Marteau J , Bouvier S , Risbet M , Favergeon J 
Published: August 2022

Abstract
This study is focused on a through characterization of the microstructure and chemical composition of dissimilar linear friction welded joints. First, Ti-6Al-2Sn-4Cr-2Mo (Ti6242) and Ti-5Al-2Sn-2Zr-4Mo-4Cr (Ti17) joints are described to identify the mechanisms behind the successful cohesion of the material surfaces. It was found that continuous dynamic recrystallization and cohesion took place through grain-boundary migration in a shared single phase β-domain obtained through high temperature and high strain conditions. Then, the possibility of assembling Ti6242 and Inconel 718 is examined. Chemical results combined with microstructure and crystal orientation analyses showed that the intermixing zone formed between the materials was particularly heterogeneous, with the development of an intermediate bimodal microstructure, mainly composed of Ti-β phase and Ti2Ni intermetallic phase.
Solid solution hardening effects on structure evolution and mechanical properties of nanostructured binary and high entropy alloys after high pressure torsion
Authors: Keil T , Minnert C , Bruder E , Durst K 
Published: August 2022

Abstract
Two different alloy series (Cu-X, Ni-X) have been selected to investigate the effects of solutes on the saturation grain size, the thermal stability and mechanical properties after high pressure torsion. The results of the Cu-X series indicate that the saturation grain size does not correlate with the stacking fault energy but shows good agreement with solid solution hardening according to the Labusch model. This correlation does not only hold for binaries, but also for chemically complex high entropy alloys (Ni-X) in the form of (CrMnFeCo)xNi1-x, where the Varvenne model is used to describe solid solution hardening. The alloy series exhibit a grain size in the range of 50 – 425 nm after high pressure torsion and the solutes increase the strength as well as the thermal stability of the alloys after annealing. The nanostructured alloys exhibit an enhanced strain rate sensitivity exponent, as determined from nanoindentation strain rate jump and constant contact pressure creep testing, whereas an enhanced rate sensitivity is found at low strain rates. The relatively lower rate sensitivity of the alloys as well as their higher thermal stability indicate, that defect storage and annihilation is strongly influenced by a complex interaction of solutes, dislocations and grain boundaries.
Analysis of inter- and intragranular variations based on 3DXRD data and crystal plasticity
Authors: Juul N Y , Oddershede J , Beaudoin A , Winther G 
Published: August 2022

Abstract
The synchrotron-based technique of 3DXRD/HEDM has proven a powerful tool to investigate individual grains in the bulk of a polycrystal during plastic deformation. Comparisons between such experimental data and crystal plasticity simulations typically show agreement with respect to overall qualitative trends. However, comparisons at the level of individual grains are in general less successful. Experimental observations and crystal plasticity simulations for a number of representative grains are analysed for similarities and differences in order to elucidate the origin of these. The comparison points at insufficient modelling of grain interactions, hardening and possibly also in the handling of ambiguities. Spatially resolved experimental data on the orientation spread is expected to provide the information needed to improve the predictive capacity at the level of individual grains.
Recrystallization kinetics of cold rolled Gum Metal
Authors: Lindkvist A , Holm Johansen T , Kørup Pedersen L , Zhang Y , Juul Jensen D 
Published: August 2022

Abstract
A wire of a β-Titanium alloy known as Gum Metal was cold rolled to a reduction of 80% and heat treated for times in the range 3-120 minutes at a fixed temperature of 740 °C to yield a set of partially recrystallized microstructures. The recrystallization course was evaluated by light optical microscopy and Electron Backscatter Diffraction, based on which the recrystallization kinetics was analysed using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. This analysis showed that the kinetics of this material does not follow the traditional JMAK behaviour but has two distinct stages with very different Avrami exponents.
Influence of shielding gas flow on the uniformity of additively manufactured martensitic stainless steel
Authors: Pan Z , Nadimpalli V K , Christiansen T L , Andersen S A , Kjer M B , Mishin O V , Zhang Y 
Published: August 2022

Abstract
Shielding gas flow is essential to the additive manufacturing (AM) process, and the effects of argon shielding gas flow variation on the macroscopic homogeneity of additive manufactured stainless steel parts have been studied using an open-architecture AM system. Such a variation manifests itself layer-by-layer within one part and part-by-part across the build plate. Within one build, a combination of balling behavior, conduction melting and keyhole melting is observed across the build plate using the same laser parameters. Quantitative characterization of the melt pool shapes show that the melt pool width and the penetration depth exhibit the largest variations. Possible relations between the gas flow condition and macroscopic structure variations are discussed and guidelines for improved design of a gas flow system as well as future research directions are suggested for achieving macroscopically uniform metal AM.
3D characterization of a nanostructured Al-Cu-Mg alloy
Authors: Zhu Wanquan , Yang Ran , Feng Zongqiang , Wu Guilin , Godfrey Andrew , Huang Xiaoxu 
Published: August 2022

Abstract
Three-dimensional (3D) characterization of variations in crystallography and chemistry of nanostructured metals will provide vital information to understand their mechanical and thermal behaviours. This study applied a surface sliding friction treatment (SSFT) at liquid nitrogen temperature to produce nanostructured surface layers in a peak-aged Al-Cu-Mg alloy. The nanostructured surface was characterized by means of 3D orientation mapping in the transmission electron microscope (3D-OMiTEM) and atom probe tomography (APT). 3D-OMiTEM results revealed a lamellar structure with an average lamellar boundary spacing of 26 nm at the topmost surface layer (depth < 20 μm), which is much finer than normally achievable in commercial purity Al deformed to high strain levels. Based on the 3D-OMiTEM data, a five-parameter grain boundary character analysis was carried out. It was found that low angle grain boundaries dominate the nanoscale structure and that the grain boundary plane distribution of high angle lamellar grain boundaries shows a preference around {101}. APT analysis showed segregation of Cu and Mg atoms at lamellar boundaries, which is believed to play a role in stabilizing the boundaries and enhancing the structural refinement during SSFT.
Effect of inclusion type on the rotating bending fatigue properties of a high carbon chromium bearing steel
Authors: Shi Zhiyue , Cao Wenquan , Shang Chengjia , Zhang Xiaodan 
Published: August 2022

Abstract
The use of the double vacuum melting route (conventional second refining + vacuum arc refining, CSR+VAR) and the electroslag remelting route (vacuum induction melting + electroslag remelting, VIM+ESR)) has been investigated for the SAE52100 (100Cr6) bearing steel. The tensile properties, impact toughness, hardness and RCF life of the CSR+VAR steel and the steel prepared using the VIM+ESR route are similar. The number and size of TiN inclusions in the VIM+ESR steel are higher and larger than those in the CSR+VAR steel, providing an explanation for the observation of better fatigue properties for the CSR+VAR steel. Two major types of inclusions, magnesium aluminates/Al2O3-CaO-CaS and TiN, are located in different areas in a map of stress intensity factor versus rotatory bending fatigue cycles (NRBF
). The negative impact of TiN inclusions on fatigue properties are greater than those of magnesium aluminates/Al2O3-CaO-CaS inclusions.
In-situ study of microstructural evolution and strain distribution during single axis tension of 316L stainless steel prepared by selective laser melting
Authors: Wang W Y , Gao W Q , Sun S , Godfrey A 
Published: August 2022

Abstract
A combined digital image correlation (DIC) and electron backscatter diffraction (EBSD) study of the multi-scale strain distribution and microstructure evolution during tensile loading has been carried on 316L stainless steel samples prepared by selective laser melting (SLM). The initial material shows a range of microstructural heterogeneity. Macro- and micro-DIC results reveal a non-uniform distribution of plastic strain over several length scales, including the formation of localized slip-bands at the intra-grain level. No obvious correlation is found between the heterogeneity in plastic strain and either grain size, grain morphology or the orientation of the cellular structures formed during SLM. Intragranular orientation subdivision and the evolution of local misorientation have also been investigated by EBSD during tension, where a complex pattern of heterogeneity in both microstructure and plastic strain is found.
Microplasticity in inhomogeneous alloys
Authors: Pachaury Yash , Kumagai Tomohisa , El-Azab Anter 
Published: August 2022

Abstract
We report on a preliminary modelling effort to understand the influence of compositional inhomogeneity on alloy microplasticity from a dislocation dynamics perspective. We tackle this problem by multiscale simulations in three steps: (1) analysis of the 3D composition morphology in alloys with tendency to undergo spinodal instability both thermally and under irradiation, with bcc FeCrAl alloys as a model system, (2) atomistic simulation of the dislocation mobility as a function of the local alloy composition, and (3) using dislocation dynamics simulations to understand the impact of composition inhomogeneity on microplasticity. The dislocation dynamics model takes into consideration the coherency stress associated with composition inhomogeneity when computing the forces driving the dislocation motion and on cross slip. Our preliminary investigation shows that the stress-strain response of the alloy and the dislocation density evolution depend on the wavelength of the composition fluctuations. Our investigation also shows that the alloy inhomogeneity may alter the cross-slip activity, which, in turn, influences the dislocation density evolution. The dependence of the dislocation mobility and coherency stress on local composition and its variation, as well as the altered cross slip rates, cause the dislocation microstructure to differ relative to that in the homogeneous alloy of the same average composition.
Multiscale Exploration of Texture and Microstructure Development in Recrystallization Annealing of Heavily Deformed Ferritic Alloys
Authors: Yildirim C , Mavrikakis N , Cook P K , Rodriguez Lamas R , Poulsen H F , Detlefs C , Kutsal M 
Published: August 2022

Abstract
We present a multi-scale study of recrystallization annealing of an 85% cold rolled Fe-3%Si-0.1%Sn alloy using a combination of dark field X-ray microscopy (DFXM), synchrotron X-ray diffraction (SXRD), and electron backscatter diffraction (EBSD). Grains of interest from high stored energy (HSE) regions in a 200μm-thick sample are studied using DFXM during isothermal annealing. The intra-granular structure of the as deformed grain reveals deformation bands separated by ≈ 3–5° misorientation. Geometrically Necessary Dislocation evolution during recrystallization and growth is investigated. These findings are supported by a quantitative non-destructive texture analysis using SXRD in terms of pole figures and orientation distribution functions. Although no significant macroscopic texture change is observed up to 50% recrystallization, the calculated texture index indicates different nucleation and growth processes at various stages of annealing. Our results show that zones of local misorientation in the HSE regions are decisive for the formation and growth of recrystallized grains.
Recent advances of lab-based diffraction contrast tomography – reconstruction speed benchmark testing and validations
Authors: Sun J , Bachmann F , Oddershede J , Lauridsen E 
Published: August 2022

Abstract
Lab-based diffraction contrast tomography (DCT) enables the user to reconstruct 3D grain maps of polycrystalline materials non-destructively. For each grain, the morphology and crystallographic orientation, as well as derived properties such as grain boundaries, can be determined. Through two application examples this paper demonstrates the data acquisition and reconstruction speed of the current implementation and validates the resulting grain maps. Firstly, for a conventional Laue focusing scan of an AlCu sample comprising 340 grains, major performance enhancements of the reconstruction algorithm have reduced the reconstruction time from half a day to half an hour. The second example highlights an advanced scan with projection geometry of an oriented electrical steel sheet containing 7,800 grains. While the data collection time is around a day for each of the data sets, the boosted reconstruction of the advanced acquisition data takes half a day and gives the full grain map without the need for stitching. After the major algorithm speed enhancements, grain map qualities are comparable with misorientations below 0.02° and grain boundary distances less than a voxel for both samples.
A simple procedure to produce bio-mimic brick-and-mortar microstructure in commercially pure Ti
Authors: Liu Chengze , Xu Jianping , Li Huan , Zhang Yusheng 
Published: August 2022

Abstract
The extremely high fracture toughness of nacre is known to arise from its brick-and-mortar microstructure and has inspired the development of metals, metallic glasses and composites with similar bio-mimic microstructures. Although various approaches have been proposed to produce materials with a brick-and-mortar microstructure, including powder metallurgy, electro deposition, spray deposition, etc., the production of large-scale samples remains to be a challenge. In this research, we present a simple way to produce large samples of commercially pure Ti with a brick-and-mortar microstructure, which includes a pre-heat-treatment followed by deformation in the single-phase temperature region and subsequent annealing. EBSD characterization shows a layered microstructure in the produced samples resembling a brick-and-mortar structure.
Texture in cold rolled and high-temperature annealed Cu foils
Authors: Guo J , Li X , Wu G L , Zhang R Q , Huang T L , Shi H F , Zhang C L , Jensen D , Huang X 
Published: August 2022

Abstract
Thick single crystal Cu foil substrates with specific crystallographic orientations such as {111} and {110} planes parallel to the rolling plane are desired for epitaxial growth of two-dimensional materials such as graphene. In this study, annealing experiments of a 46 μm thick cold-rolled foil were carried out at temperatures in the range of 300-1040 °C. The texture evolution during annealing was followed by electron backscatter diffraction (EBSD) orientation mapping. It was found that the texture evolution may be divided into three stages: at relatively low annealing temperatures, a strong cube texture develops with a small population of grains having relatively larger deviations from the cube orientation; at medium temperatures, these grains with large deviations grow abnormally; and at the highest temperature, annealing twins form in the abnormally growing grains giving rise to new orientations including some with the {111} planes parallel to the rolling plane.
Effect of Aging Treatment on the Microstructure and Mechanical Properties of Fe-Mn-Al-C Low Density Steel
Authors: Li G Y , Kong L , Liu E Z , Zhang X D , Cao W Q , Wang Y H 
Published: August 2022

Abstract
Fe-Mn-Al-C steel has excellent weight reduction potential. In this study, the microstructure and mechanical properties of Fe-25Mn-11Al-1.0C steel after solution treatment at 1050 °C and aging at 450~650 °C are studied. The results show that with the increase of aging temperature, the strength increases first and then decreases. The plasticity and strength show a trade-off relationship. With the increase of the aging temperature, the plasticity first decreases and then increases. The above-mentioned changes in mechanical properties are closely related to the changes in the morphology and distribution of κ-carbides during the aging process. In general, the precipitation of κ-carbides is beneficial to obtain higher strength, but has a detrimental effect on plasticity.
Microstructure and mechanical properties of a 0.1C5Mn3Al steel fabricated by warm drawing
Authors: Zhang L , Cai P , Cheng X , Zhang L , Hou Z , Huang X 
Published: August 2022

Abstract
In the present study, a recently developed low density 0.1C5Mn3Al dual phase steel was subjected to warm drawing at 600 °C. Microstructure observations and mechanical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tensile tests. It was found that carbide precipitates together with laminated ferrite were formed before and after warm drawing. After warm drawing by a Von Mises strain of 1.96, the yield stress (YS) improved from 650 MPa to 1100 MPa and the uniform elongation (UE) dropped to 2%. Further heat treatments were performed to tune the microstructures and mechanical properties. Discontinuous yielding phenomenon was widely observed in the heat treated samples and 15% hot rolling was used to eliminate this discontinuous yielding.
Recrystallization kinetics of the AA5xxx series aluminum alloys - revisited
Authors: Vandermeer Roy , Lin Fengxiang , Lei Xiuchuan , Sanders Robert Edward , Jensen Dorte Juul 
Published: August 2022

Abstract
In previous work [1], we analyzed the recrystallization kinetics in cold-rolled AA5657 and AA5182 based on measurements of the volume fraction of recrystallized material, the free (unimpinged) surface area density and the average size of the recrystallizing grains, plus the contiguity between recrystallizing grains, for a series of partially recrystallized samples. In that work, the calculated growth and nucleation rates were used as basis from the analysis. These two properties are derived from the measured parameters, which, as shown in the present work, adds to their uncertainty. In the present paper, we revisit the kinetics using improved stereological data and perform a full microstructural path analysis. The new analysis results are compared to the previous ones and the implications of using the different types of data sets and analytical approach for the interpretation of the kinetics are discussed.
The Effect of Compositional Heterogeneity on the Martensite Start Temperature of a High Strength Steel During Rapid Austenitisation and Cooling
Authors: Taylor M , Fellowes J W , Hill P O , Rawson M J , Burnett T L , Pickering E J 
Published: August 2022

Abstract
Many low alloy steels are compositionally heterogeneous due to the preferential segregation of alloying elements to the dendritic or interdendritic regions when the steel is first solidified (microsegregation). This segregation is often ignored when using CCT diagrams to predict the phase transformation behaviour of steels, but may be of importance in some industrially-relevant cases. This work focuses on the martensite start temperature (Ms
) of Super CMV, a high strength aerospace steel, after rapid austenitisation treatment to various peak temperatures from 900 °C to 1300 °C. It was found that the average Ms
temperature increased with increasing peak temperature (and prior austenite grain size) at peak temperatures of 1100°C and above, which is to be expected conventionally. However, at peak temperatures of below 1100°C, the Ms
temperature increased with decreasing prior-austenite grain size. It is proposed that this was due to the presence of non-dissolved carbides in these conditions, particularly in enriched bands of material, which deplete the matrix and hence raise Ms
.
Dislocation sub-structures, recovery and recrystallization in pure tantalum
Authors: Moussa C , Baton J , Geslin W 
Published: August 2022

Abstract
Plastic deformation, static recovery and recrystallization in pure tantalum are analyzed in the present paper. Quantitative analysis of dislocation sub-structures were done. Sub-structures development is completely dependent on crystallographic orientation. No clear effect of recovery was observed when direct analysis was made. Hence, recovery was studied through its effect on recrystallization. Recovery heat treatments followed by a recrystallization heat treatment were applied to compare the recrystallized state of samples which were subject to prior recovery with those which were not. Results show that recrystallization is accelerated in the early stages of recovery (low temperature or low annealing time or low plastic strain). On the opposite, in the advanced stages of recovery, it slows down recrystallization. Results show again an influence of crystallographic orientation. Static recrystallization was also investigated and the influence of crystallographic orientation, most probably inherited from the deformed state through dislocation sub-structures, was observed. Based on experimental results, a discussion on the mechanisms of nucleation in the different orientation grains is presented. Finally, a discussion is made on the quantification of stored energy. The effect of the observation scale and the choices of considering dislocation density or dislocation sub-boundaries energies from EBSD data is discussed.
Stored energy calculation in AA 1050 based on deformation microstructure from electron backscatter diffraction data
Authors: Yan Yingrui , Pan Hongjiang , Godfrey Andy , Jensen Dorte Juul , Zhang Xiaodan 
Published: August 2022

Abstract
An AA1050 aluminum plate was cold rolled to a true strain of 1.9, and the stored energy was calculated based on microstructural parameters, namely the dislocation boundary spacing and the misorientation distribution, determined from large area electron back-scatter diffraction maps with an indexed fraction higher than 90% before any data cleaning operations. Three methods were used to determine the dislocation boundary spacing and the misorientation distribution. The results show significant differences in the dislocation boundary spacings and the misorientation distributions obtained by the different methods, especially for boundaries with misorientation angles below 2°. These deviations lead to significant differences in the calculated stored energy. A discussion of the three approaches to determine stored energies is presented.