| 1. |
- Jensen, D. Juul, et al.
(författare)
-
Importance of local structural variations on recrystallization
- 2013
-
Ingår i: Material Science Forum. - : Trans Tech Publications Inc.. - 9783037856888 ; , s. 37-41
-
Konferensbidrag (refereegranskat)abstract
- Effects of local variations in the deformation microstructure on subsequent recrystallization are discussed and illustrated by three examples. The three examples consider local variations on different length scales and are: 1. Effects of local variations in the deformation microstructure on the formation of protrusions on migrating boundaries. 2. Effects of an inhomogeneous spatial distribution of second phase particles on growth. 3. Effects of stored energy and orientation variations on recrystallization kinetics.
|
|
| 2. |
- Danish, M., et al.
(författare)
-
The Effect of Chelating Agents on Enhancement of 1,1,1-Trichloroethane and Trichloroethylene Degradation by Z-nZVI-Catalyzed Percarbonate Process
- 2016
-
Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 227:9
-
Tidskriftsartikel (refereegranskat)abstract
- This study primarily focused on the performance of 1,1,1-trichloroethane (1,1,1-TCA) and trichloroethylene (TCE) degradation involving redox reactions in zeolite-supported nanozerovalent iron composite (Z-nZVI)-catalyzed sodium percarbonate (SPC) system in aqueous solution with five different chelating agents (CAs) including oxalic acid (OA), citric acid monohydrate (CAM), glutamic acid (GA), ethylenediaminetetraacetic acid (EDTA), and L-ascorbic acid (ASC). The experimental results showed that the addition of OA achieved almost 100 % degradation of 1,1,1-TCA and TCE. The addition of CAM and GA also significantly increased the contaminant degradation, while excessive addition of them inhibited the degradation. In contrast, EDTA and ASC showed negative impacts on 1,1,1-TCA and TCE degradation, which might be due to the strong reactivity with iron and OH● scavenging characteristics. The efficiency with CA addition on 1,1,1-TCA and TCE degradation decreased in the order of OA > CAM > GA > no CAs > EDTA > ASC. The extensive investigations using probe compound tests and scavenger tests revealed that both contaminants degraded primarily by OH● and O2 –● in chelated Z-nZVI-catalyzed SPC system. The significant improvement in 1,1,1-TCA and TCE degradation efficiency was accredited due to the (i) increase in concentration of Fe2+ and (ii) continuous generation of OH● radicals and maintenance of its quantity, ensuring more stability in the aqueous solution. Finally, the complete mineralization of 1,1,1-TCA and TCE in the OA-chelated, Z-nZVI-catalyzed SPC system was confirmed without any chlorinated intermediate by-products detected, demonstrating a great potential of this technique in the application of groundwater remediation.
|
|
| 3. |
|
|
| 4. |
- Lin, Fengxiang, et al.
(författare)
-
Effects of structural heterogeneity of nanostructured copper on the evolution of the sizes of recrystallized grains during annealing
- 2015
-
Ingår i: IOP Conference Series. - : Institute of Physics (IOP).
-
Konferensbidrag (refereegranskat)abstract
- Recrystallization in copper deformed by dynamic plastic deformation was investigated using electron backscatter diffraction. The recrystallized grains show a broad size distribution. The kinetics of grains of different sizes is observed to be different: In the beginning of recrystallization, the area fraction of small recrystallized grains increases rapidly. At later stages of recrystallization, the area fraction of small recrystallized grains is stable, while the area fractions of medium and large recrystallized grains increase. Correlation between the broad grain size distribution (and its evolution) and the heterogeneous deformed microstructure is discussed. © Published under licence by IOP Publishing Ltd.
|
|
| 5. |
- Lin, Fengxiang, et al.
(författare)
-
Importance of Non-uniform Boundary Migration for Recrystallization Kinetics
- 2018
-
Ingår i: Metallurgical and Materials Transactions. A. - : Springer Science and Business Media LLC. - 1073-5623 .- 1543-1940. ; 49:11, s. 5246-5258
-
Tidskriftsartikel (refereegranskat)abstract
- Recrystallization kinetics is studied by three characterization methods: post-mortem electron microscopy, in situ three-dimensional X-ray diffraction (3DXRD), and ex situ electron microscopy. Cold-rolled copper is used as a model material. The post-mortem analysis shows that the average migration velocity of unimpinged recrystallizing boundaries decreases strongly with annealing time, leading to a low Avrami exponent. For individual grains, the in situ 3DXRD measurement reveals that the growth rates decrease significantly shortly after nucleation. This is explained by the ex situ characterizations, which show that different segments of the recrystallizing boundaries migrate with significantly different velocities, and some boundaries, although unimpinged, remain stationary. This non-uniform migration of recrystallizing boundaries leads to an amoeba-like growth, and is proposed to be responsible for the decrease of the average boundary migration velocity, because the fraction of slowly moving/stationary boundaries increases during the recrystallization. Reasons for stationary boundaries are discussed based on a quantitative analysis of the local deformed microstructure. It is concluded that non-uniform boundary migration has a significant influence on recrystallization kinetics and needs to be included in recrystallization models. © 2018, The Minerals, Metals & Materials Society and ASM International.
|
|
| 6. |
- Lin, Fengxiang, et al.
(författare)
-
Local strain distributions in partially recrystallized copper determined by in situ tensile investigation
- 2015
-
Ingår i: IOP Conference Series. - : Institute of Physics Publishing (IOPP).
-
Konferensbidrag (refereegranskat)abstract
- A partially recrystallized copper sample produced by cold-rolling and annealing was deformed in situ by uniaxial tension in a scanning electron microscope, and electron backscatter diffraction data were collected before and after deformation to certain strains. The local strain distributions are quantified using digital image correlation. Distributions of the normal strain along the tensile direction (εxx) are shown in this paper. The recrystallized grains are found to deform more than the remaining unrecrystallized matrix. When εxx is averaged along lines perpendicular to the tensile direction, significant variation are observed, which may be related to the local recrystallized volume fraction. © Published under licence by IOP Publishing Ltd.
|
|
| 7. |
- Lin, Fengxiang, et al.
(författare)
-
Supercube grains leading to a strong cube texture and a broad grain size distribution after recrystallization
- 2015
-
Ingår i: Philosophical Magazine. - : Taylor & Francis. - 1478-6435 .- 1478-6443. ; 95:22, s. 2427-2449
-
Tidskriftsartikel (refereegranskat)abstract
- This work revisits the classical subject of recrystallization of cold-rolled copper. Two characterization techniques are combined: three-dimensional X-ray diffraction using synchrotron X-rays, which is used to measure the growth kinetics of individual grains in situ, and electron backscatter diffraction, which is used for statistical analysis of the microstructural evolution. As the most striking result, the strong cube texture after recrystallization is found to be related to a few super large cube grains, which were named supercube grains. These few supercube grains become large due to higher growth rates. However, most other cube grains do not grow preferentially. Because of the few supercube grains, the grain size distribution after recrystallization is broad. Reasons for the higher growth rates of supercube grains are discussed, and are related to the local deformed microstructure. © 2015 Taylor & Francis.
|
|
| 8. |
|
|
| 9. |
- Solis, Jorge, 1976-, et al.
(författare)
-
Japan-Sweden Academia-industry international collaboration : Challenges in developing a robotic assistive eating device for frail elderly's independent life
- 2017
-
Ingår i: CEUR Workshop Proceedings, Volume 2059. - : RWTH Aachen University. ; , s. 61-65, s. 61-65
-
Konferensbidrag (refereegranskat)abstract
- This project aims at making a mock-up of a multi grip tool for a robotic assistive device and a camera system which enable frail elderly to live more independently and to keep track of their food intake. The robot will be developed through user centered design with analyses of real use cases in Japan and Sweden. Thanks to the collaborating researchers with a strong applied research approach as well as the companies with a strong experience in engineering solutions in both the Japanese and Swedish teams, the functionalities of Bestic, an assistive eating device, could be enhanced for commercial use, and distributed to municipalities and to the general pub.
|
|
| 10. |
- Xu, C., et al.
(författare)
-
Crystallographic Analysis of Nucleation at Hardness Indentations in High-Purity Aluminum
- 2016
-
Ingår i: Metallurgical and Materials Transactions. A. - : Springer. - 1073-5623 .- 1543-1940. ; 47:12, s. 5863-5870
-
Tidskriftsartikel (refereegranskat)abstract
- Nucleation at Vickers hardness indentations has been studied in high-purity aluminum cold-rolled 12 pct. Electron channeling contrast was used to measure the size of the indentations and to detect nuclei, while electron backscattering diffraction was used to determine crystallographic orientations. It is found that indentations are preferential nucleation sites. The crystallographic orientations of the deformed grains affect the hardness and the nucleation potentials at the indentations. Higher hardness gives increased nucleation probabilities. Orientation relationships between nuclei developed at different indentations within one original grain are analyzed and it is found that the orientation distribution of the nuclei is far from random. It is suggested that it relates to the orientations present near the indentation tips which in turn depend on the orientation of the selected grain in which they form. Finally, possible nucleation mechanisms are briefly discussed. © 2016, The Minerals, Metals & Materials Society and ASM International.
|
|
