Journal articles: 'Deformation mechanism maps'

1

Greenwood, G. W. "Deformation mechanism maps and microstructural influences." Materials Science and Engineering: A 410-411 (November 2005): 12–15. http://dx.doi.org/10.1016/j.msea.2005.08.098.

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2

Rybacki, Erik, and Georg Dresen. "Deformation mechanism maps for feldspar rocks." Tectonophysics 382, no. 3-4 (April 2004): 173–87. http://dx.doi.org/10.1016/j.tecto.2004.01.006.

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3

Hou, Qing Yu, and Jing Tao Wang. "Deformation Mechanism in the Mg-Gd-Y Alloys Predicted by Deformation Mechanism Maps." Advanced Materials Research 146-147 (October 2010): 225–32. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.225.

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Deformation mechanism maps at 0-883 K and shear strain rate of 10-10-10+6 s-1 were built from available rate equations for deformation mechanisms in pure magnesium or magnesium alloys. It can be found that the grain size has little effect on the fields of plasticity and phonon or electron drag, though it has important influence on the fields of power-law creep, diffusion creep, and Harper-Dorn creep in the maps within the present range of temperature, strain rate, and grain size. A larger grain size is helpful to increase the field range of power-law creep but decrease that of diffusion creep when the grain size is smaller than ~204 μm. Harper-Dorn creep dominates the deformation competed to diffusion creep in the grain size range of ~204-255 μm. The maps include only plasticity, phonon or electron drag, and power-law creep when the grain size is higher than ~255 μm, then the grain size has little influence on the maps. Comparison between the reported data for the Mg-Gd-Y alloys and the maps built from available rate equations, it can be conclude that the maps are an effective tool to predict or achieve a comprehensive understanding of the deformation behavior of the Mg-Gd-Y alloys and to classify systematically their discrepancies in the deformation mechanism. However, differences exist in the deformation mechanisms of the alloys observed by the reported data and that predicted by the maps. Therefore, refinement of the maps from the viewpoint of mechanical twining, DRX, and adiabatic shear are necessary.

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Kim, W. J., and H. T. Jeong. "Construction of processing maps combined with deformation mechanism maps using creep deformation equations." Journal of Materials Research and Technology 9, no. 6 (November 2020): 13434–49. http://dx.doi.org/10.1016/j.jmrt.2020.09.023.

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5

Misra, A., M. Verdier, H. Kung, J. D. Embury, and J. P. Hirth. "Deformation mechanism maps for polycrystalline metallic multiplayers." Scripta Materialia 41, no. 9 (October 1999): 973–79. http://dx.doi.org/10.1016/s1359-6462(99)00239-0.

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6

Lee, I. G., and A. K. Ghosh. "High Temperature Deformation Mechanism Maps of NiAl." Materials Science Forum 449-452 (March 2004): 57–60. http://dx.doi.org/10.4028/www.scientific.net/msf.449-452.57.

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In order to analyze high temperature deformation behavior of NiAl alloys, deformation maps were constructed for stoichiometric NiAl materials with grain sizes of 4 and 200 µm. Relevant constitute equations and calculation method will be described in this paper. These maps are particularly useful in identifying the location of testing domains, such as creep and tensile tests, in relation to the stress-temperature-strain rate domains experienced by NiAl.

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Misra, A., M. Verdier, H. Kung, J. D. Embury, and J. P. Hirth. "Erratum deformation mechanism maps for polycrystalline metallic multilayers." Scripta Materialia 42, no. 2 (December 1999): 219. http://dx.doi.org/10.1016/s1359-6462(99)00413-3.

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8

Langdon, Terence G. "Deformation mechanism maps for applications at high temperatures." Ceramics International 11, no. 4 (October 1985): 141. http://dx.doi.org/10.1016/0272-8842(85)90165-8.

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9

Wang, Jian N., and T. G. Nieh. "Incorporation of peierls stress into deformation mechanism maps." Scripta Metallurgica et Materialia 33, no. 4 (August 1995): 633–38. http://dx.doi.org/10.1016/0956-716x(95)00230-s.

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10

Xie, De-Gang, Rong-Rong Zhang, Zhi-Yu Nie, Jing Li, Evan Ma, Ju Li, and Zhi-Wei Shan. "Deformation mechanism maps for sub-micron sized aluminum." Acta Materialia 188 (April 2020): 570–78. http://dx.doi.org/10.1016/j.actamat.2020.02.013.

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11

Zhou, Ge, Lijia Chen, Lirong Liu, Haijian Liu, Heli Peng, and Yiping Zhong. "Low-Temperature Superplasticity and Deformation Mechanism of Ti-6Al-4V Alloy." Materials 11, no. 7 (July 13, 2018): 1212. http://dx.doi.org/10.3390/ma11071212.

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The low-temperature superplastic tensile behavior and the deformation mechanisms of Ti-6Al-4V alloy are investigated in this paper. Through the experiments carried out, elongation to failure (δ) is calculated and a set of values are derived that subsequently includes the strain rate sensitivity exponent (m), deformation activation energy (Q) at low-temperature superplastic deformation, and the variation of δ, m and Q at different strain rates and temperatures. Microstructures are observed before and after superplastic deformation. The deformation mechanism maps incorporating the density of dislocations inside grains at temperatures of 973 and 1123 K are drawn respectively. By applying the elevated temperature deformation mechanism maps based on Burgers vector compensated grain size and modulus compensated stress, the dislocation quantities and low-temperature superplastic deformation mechanisms of Ti-6Al-4V alloy at different temperatures within appropriate processing regime are elucidated.

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12

Monteiro, Sergio Neves, Frederico Muylaert Margem, Lucas Tedesco Bolzan, George Lobo Nobre Fernandes, and Verônica Scarpini Cândido. "Special Effects in Deformation Mechanism Maps for Austenitic Stainless Steels." Materials Science Forum 869 (August 2016): 543–49. http://dx.doi.org/10.4028/www.scientific.net/msf.869.543.

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The domains of the existence of deformation mechanisms in a map associated with phase transformation and mechanical effects related to aging processes were investigated in austenitic stainless steels. It was also discussed the participation of grain boundary sliding, both as an additional deformation mechanism and a damage accumulation process. A prediction analysis for two typical high temperature engineering systems was attempted based on the map information. This prediction indicates the possibility of grain boundary sliding and creep strain jumps to interfere with the expected operational life of components in these systems operating at high temperatures.

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13

Cheng, Bin, and Jason R. Trelewicz. "Design of crystalline-amorphous nanolaminates using deformation mechanism maps." Acta Materialia 153 (July 2018): 314–26. http://dx.doi.org/10.1016/j.actamat.2018.05.006.

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14

Liu, Chao, Ge Zhou, Xin Wang, Jiajing Liu, Jianlin Li, Haoyu Zhang, and Lijia Chen. "Rheological Law and Mechanism for Superplastic Deformation of Ti–6Al–4V." Materials 12, no. 21 (October 26, 2019): 3520. http://dx.doi.org/10.3390/ma12213520.

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The behaviors of and mechanisms acting in Ti–6Al–4V alloy during low-temperature superplastic deformation were systematically studied by using a Gleeble-3800 thermocompression simulation machine. Focusing on the mechanical behaviors and microstructure evolution laws during low-temperature superplastic compression tests, we clarified the changing laws of the strain rate sensitivity index, activation energy of deformation, and grain index at varying strain rates and temperatures. Hot working images based on the dynamic material model and the deformation mechanism maps involving dislocation quantity were plotted on the basis of PRASAD instability criteria. The low-temperature superplastic compression-forming technique zone and the rheological instability zone of Ti–6Al–4V were analyzed by using hot processing theories. The dislocation evolution laws and deformation mechanisms of the grain size with Burgers vector compensation and the rheological stress with modulus compensation during the low-temperature superplastic compression of Ti–6Al–4V were predicted by using deformation mechanism maps.

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15

Li, M., and SJ Zinkle. "Deformation Mechanism Maps of Unirradiated and Irradiated V-4Cr-4Ti." Journal of ASTM International 2, no. 10 (2005): 12462. http://dx.doi.org/10.1520/jai12462.

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16

Koleshko, V. M., and I. V. Kiryushin. "Deformation mechanism maps and gettering diagrams for single-crystal silicon." Physica Status Solidi (a) 109, no. 1 (September 16, 1988): 161–69. http://dx.doi.org/10.1002/pssa.2211090116.

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17

Till, J. L., and Bruce Moskowitz. "Magnetite deformation mechanism maps for better prediction of strain partitioning." Geophysical Research Letters 40, no. 4 (February 27, 2013): 697–702. http://dx.doi.org/10.1002/grl.50170.

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18

Becker, Hanka, and Wolfgang Pantleon. "Work-hardening stages and deformation mechanism maps during tensile deformation of commercially pure titanium." Computational Materials Science 76 (August 2013): 52–59. http://dx.doi.org/10.1016/j.commatsci.2013.03.028.

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19

Freeman, Brett, and Colin C. Ferguson. "Deformation mechanism maps and micromechanics of rocks with distributed grain sizes." Journal of Geophysical Research: Solid Earth 91, B3 (March 10, 1986): 3849–60. http://dx.doi.org/10.1029/jb091ib03p03849.

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20

Robi, P. S., Sanjib Banerjee, and A. Srinivasan. "Deformation Mechanism Maps for Al-Cu-Mg Alloys Micro-Alloyed with Tin." Advanced Materials Research 410 (November 2011): 283–86. http://dx.doi.org/10.4028/www.scientific.net/amr.410.283.

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High temperature deformation behavior of Al–5.9%Cu–0.5%Mg alloy and Al–5.9%Cu–0.5%Mg alloy containing 0.06 wt.% of Sn was studied by hot compression tests at various temperatures and strain rates. Addition of trace amounts of Sn into the Al–Cu–Mg alloy system resulted in a significant increase of flow stress for all conditions of temperature and strain rate. 100% and 89% of the flow stress values during hot deformation could be predicted within ± 10% deviation values for the aluminum alloys with and without Sn content, respectively, by artificial neural network (ANN) modeling. From the deformation mechanism maps and microstructural investigation, the safe process regimes for hot working of the base alloy was identified to be at (i) very low strain rate (< 0.003 s−1) at temperature < 450 °C, and (ii) high temperature (> 400 °C) with strain rate > 0.02 s−1. For the micro-alloyed alloy, it was at low strain rates (< 0.01 s-1) for the entire temperature range studied. Flow softening for both alloys was observed to be at low strain rates and was identified to be due to dynamic recrystallization (DRX). The metallurgical instability during deformation was identified due to shear band formation and/or inter-crystalline cracking.

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21

Cao, Furong. "Incorporating dislocation variables into Mohamed's and Kawasaki–Langdon's deformation mechanism maps containing superplasticity mechanism regimes." Materials Science and Engineering: A 643 (September 2015): 169–74. http://dx.doi.org/10.1016/j.msea.2015.07.042.

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22

Kawasaki, Megumi, and Terence G. Langdon. "Evaluating the Flow Properties of Ultrafine-Grained Materials." Advanced Materials Research 829 (November 2013): 3–9. http://dx.doi.org/10.4028/www.scientific.net/amr.829.3.

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Processing through the application of severe plastic deformation (SPD) provides an opportunity for achieving significant grain refinement, typically to the submicrometer or even the nanometer level. If these small grains are reasonably stable at elevated temperatures, it is possible to achieve excellent superplastic capabilities at very rapid strain rates. Recent developments on the flow properties of ultrafine-grained materials are examined and it is shown that the flow mechanisms can be readily depicted using deformation mechanism maps. Examples of maps are presented for materials processed by SPD techniques.

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23

Mohamed, Farghalli A. "Deformation mechanism maps for micro-grained, ultrafine-grained, and nano-grained materials." Materials Science and Engineering: A 528, no. 3 (January 2011): 1431–35. http://dx.doi.org/10.1016/j.msea.2010.10.048.

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24

Ullmann, Madlen, Matthias Schmidtchen, Kristina Kittner, Thorsten Henseler, Rudolf Kawalla, and Ulrich Prahl. "Hot Deformation Behaviour and Processing Maps of an as-Cast Mg-6.8Y-2.5Zn-0.4Zr Alloy." Materials Science Forum 949 (March 2019): 57–65. http://dx.doi.org/10.4028/www.scientific.net/msf.949.57.

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Deformation behavior of an as-cast Mg-6.8Y-2.5Zn-0.4Zr alloy during plane strain compression was characterized in present work by high-temperature testing. Based on the experimental data, the values of strain rate sensitivity, efficiency of power dissipation and the instability parameter under the condition of various hot working parameters were investigated. Processing maps were established by superimposing the instability map over the power dissipation map, this being connected with microstructural evolution analysis in the hot deformation processes. Accompanied microstructure characterization of the binary α-Mg/ Long Period Stacking Ordered (LPSO) microstructure reveals that the flow behavior is related to the deformation mechanisms. At lower temperatures (350 – 400 °C) formation of kink bands is observed, which normally occur when deformation twinning is inhibited and other slip systems are strongly hindered by the complex LPSO structures. Dynamic recrystallization (DRX) was initiated at higher temperatures above 400 °C, influencing the softening behavior of the material significantly. DRX was the main softening mechanism when deformation takes place at 500 °C and the kink band deformation decreased.

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25

Jeong, H. T., and W. J. Kim. "Calculation and construction of deformation mechanism maps and processing maps for CoCrFeMnNi and Al0.5CoCrFeMnNi high-entropy alloys." Journal of Alloys and Compounds 869 (July 2021): 159256. http://dx.doi.org/10.1016/j.jallcom.2021.159256.

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26

Kawasaki, Megumi, and Terence G. Langdon. "Description of the Superplastic Flow Process by Deformation Mechanism Maps in Ultrafine-Grained Materials." Materials Science Forum 838-839 (January 2016): 51–58. http://dx.doi.org/10.4028/www.scientific.net/msf.838-839.51.

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The synthesis of ultrafine-grained (UFG) materials is very attractive because small grains lead to excellent creep properties including superplastic ductility at elevated temperatures. Severe plastic deformation (SPD) is an attractive processing technique for refining microstructures of metallic materials to have ultrafine grain sizes within the submicrometer to even the nanometer level. Among the SPD techniques, most effective processing is conducted through equal-channel angular pressing (ECAP) and high-pressure torsion (HPT) and there are numerous reports demonstrating the improved tensile properties at elevated temperature. This report demonstrates recent results on superplasticity in metals after ECAP and HPT. Moreover, superplastic flow of the UFG materials is evaluated by using flow mechanisms developed earlier for coarse-grained materials and depicted by plotting deformation mechanism maps which provide excellent visual representations of flow properties over a wide range of testing conditions.

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27

Kawasaki, Megumi, Roberto B. Figueiredo, and Terence G. Langdon. "The Development of Superplasticity and Deformation Mechanism Maps in an Ultrafine-Grained Magnesium Alloy." Materials Science Forum 879 (November 2016): 48–53. http://dx.doi.org/10.4028/www.scientific.net/msf.879.48.

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Magnesium alloys with refined grain structure are often superplastic at elevated temperatures with maximum elongations up to more than 1000%. The superplastic behavior of this material agrees with deformation by grain boundary sliding. Dislocation climb becomes the rate controlling mechanism at higher stresses but the rate controlling mechanism at lower stresses is not fully documented. This report examines the development of superplasticity in a magnesium ZK60 alloy and shows that an increase in stress exponent and decrease in elongation takes place at low stresses. Deformation mechanism maps are constructed considering Regions I, II and III and Coble creep.

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28

Yang, Zhijun, Weixin Yu, Shaoting Lang, Junyi Wei, Guanglong Wang, and Peng Ding. "Hot Deformation Behavior and Processing Maps of a New Ti-6Al-2Nb-2Zr-0.4B Titanium Alloy." Materials 14, no. 9 (May 9, 2021): 2456. http://dx.doi.org/10.3390/ma14092456.

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The hot deformation behaviors of a new Ti-6Al-2Nb-2Zr-0.4B titanium alloy in the strain rate range 0.01–10.0 s−1 and temperature range 850–1060 °C were evaluated using hot compressing testing on a Gleeble-3800 simulator at 60% of deformation degree. The flow stress characteristics of the alloy were analyzed according to the true stress–strain curve. The constitutive equation was established to describe the change of deformation temperature and flow stress with strain rate. The thermal deformation activation energy Q was equal to 551.7 kJ/mol. The constitutive equation was ε ˙=e54.41[sinh (0.01σ)]2.35exp(−551.7/RT). On the basis of the dynamic material model and the instability criterion, the processing maps were established at the strain of 0.5. The experimental results revealed that in the (α + β) region deformation, the power dissipation rate reached 53% in the range of 0.01–0.05 s−1 and temperature range of 920–980 °C, and the deformation mechanism was dynamic recovery. In the β region deformation, the power dissipation rate reached 48% in the range of 0.01–0.1 s−1 and temperature range of 1010–1040 °C, and the deformation mechanism involved dynamic recovery and dynamic recrystallization.

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29

Zhou, Ge, Jianlin Li, Chao Liu, Haoyu Zhang, Xin Che, Xiaofei Zhu, and Lijia Chen. "Theoretical predication of dislocation-included high-temperature deformation mechanism maps for GH4742 alloy." Philosophical Magazine Letters 100, no. 8 (June 10, 2020): 386–91. http://dx.doi.org/10.1080/09500839.2020.1774933.

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30

Kawasaki, Megumi, and Terence G. Langdon. "Using deformation mechanism maps to depict flow processes in superplastic ultrafine-grained materials." Journal of Materials Science 47, no. 22 (April 21, 2012): 7726–34. http://dx.doi.org/10.1007/s10853-012-6487-y.

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31

Meike, A. "Dislocation enhanced selective dissolution: an examination of mechanical aspects using deformation-mechanism maps." Journal of Structural Geology 12, no. 5-6 (January 1990): 785–94. http://dx.doi.org/10.1016/0191-8141(90)90089-h.

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32

Prasad, Y. V. R. K., and K. P. Rao. "Effect of Oxygen Content on the Processing Maps for Hot Deformation of OFHC Copper." Journal of Engineering Materials and Technology 128, no. 2 (October 19, 2005): 158–62. http://dx.doi.org/10.1115/1.2172275.

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Processing map for the hot deformation of high purity oxygen free high conductivity (OFHC) copper (2ppm oxygen) has been developed in the temperature range 600-950°C and strain rate range 0.001-100s−1. The map is compared with those published earlier on OFHC copper with higher oxygen contents (11ppm and 30ppm) with a view to evaluating the effect of oxygen content on the dynamic behavior of OFHC copper and the mechanism of hot deformation. The maps reveal that dynamic recrystallization (DRX) occurs over a wide temperature and strain rate range and is controlled by different diffusion mechanisms. In OFHC copper with 2ppm oxygen, the apparent activation energy for the DRX domain in the strain rate range 0.01-10s−1 and temperature range 600-900°C is estimated to be about 137kJ∕mole which suggests dislocation core diffusion to be the rate controlling mechanism. However, this domain is absent in the maps for OFHC copper with higher oxygen content due to the “clogging” of dislocation pipes by the oxygen atoms thereby preventing this short circuit diffusion process. At strain rates in the range 1-100s−1 and temperatures >700°C, the apparent activation energy is 73kJ∕mole suggesting that DRX is controlled by grain boundary self diffusion, and this domain expands with higher oxygen content in OFHC copper. At strain rates <0.01s−1 and temperatures >750°C, lattice self-diffusion is the rate controlling mechanism and this lower strain rate domain moves to lower temperatures with increasing oxygen content.

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33

Xue, Yong, Zhi Min Zhang, and Yao Jin Wu. "A Study on Processing Map and Flow Stress Model of AZ80 Magnesium Alloy Forming at Elevated Temperature." Applied Mechanics and Materials 121-126 (October 2011): 3–9. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.3.

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Quantities AZ80 magnesium alloy billets were compressed with 60% height reduction on hot process simulator at 200,250,300,350,400,450°C under strain rates of 0.001, 0.01, 0.1,1 and 10s-1.The processing maps based on the Dynamic Material Modeling (DMM) were constructed, which is useful to analyze the deformation mechanism and the destabilization mechanism of AZ80 alloy. If the mechanical property of AZ80 alloy is taken into consideration, the optimal deformation processing parameters from the processing maps are the deformation temperatures ranging from 300 to 350°C and strain rates ranging from 0.001 to 0.01s-1. Meanwhile, a flow stress model with eight parameters is used to characterize the dynamic recrystallization strain softening of AZ80 alloy.

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34

Li, Hui, Zhanglong Zhao, Yongquan Ning, Hongzhen Guo, and Zekun Yao. "Characterization of Microstructural Evolution for a Near-α Titanium Alloy with Different Initial Lamellar Microstructures." Metals 8, no. 12 (December 10, 2018): 1045. http://dx.doi.org/10.3390/met8121045.

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The effects of initial lamellar thickness on microstructural evolution and deformation behaviors of a near-α Ti-5.4Al-3.7Sn-3.3Zr-0.5Mo-0.4Si alloy were investigated during isothermal compression in α + β phase field. Special attention was paid to microstructural conversion mechanisms for α lamellae with different initial thicknesses. The deformation behaviors, including flow stress, temperature sensitivity, and strain rate sensitivity, and processing maps and their dependence on initial lamellar thickness were discussed. The detailed microstructural characterizations in different domains of the developed processing maps were analyzed. The results showed that the peak efficiency of power dissipation decreased with increasing initial lamellar thickness. The interaction effects with different extents of globularization, elongating, kinking, and phase transformation of lamellar α accounted for the variation in power dissipation. The flow instability region appeared to expand more widely for thicker initial lamellar microstructures during high strain rate deformation due to flow localization and local lamellae kinking. The electron backscatter diffraction (EBSD) analyses revealed that the collaborative mechanism of continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) promoted the rapid globularization behavior for the thinnest acicular initial microstructure, whereas in case of the initial thick lamellar microstructure, CDRX leading to the fragmentation of lamellae was the dominant mechanism throughout the deformation process.

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35

Yang, Junzhou, and Jianjun Wu. "Grain Rotation Accommodated GBS Mechanism for the Ti-6Al-4V Alloy during Superplastic Deformation." Crystals 11, no. 8 (August 20, 2021): 991. http://dx.doi.org/10.3390/cryst11080991.

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An investigation of flow behavior and the deformation mechanism for Ti-6Al-4V alloy during the superplastic deformation process is presented in this paper. Constant strain rate tensile tests were performed at 890–950 °C and strain rates of 10−2, 10−3, and 10−4/s. Then, surface observation by Optical Microscope (OM), Scanning Electron Microscopy (SEM), and Electron Back-scattered Diffraction (EBSD) was applied to obtain the microstructure mechanism. With pole figure maps (PF) for α-phase, obvious texture gradually changed in the main deformation direction. For the titanium alloy, the evolution of texture in deformed samples was attributed to grain rotation (GR). Significant grain rearrangement occurred between grains after deformation. A complete grain rotation accommodated grain boundary sliding (GBS) deformation mechanism is proposed, which can explain texture evolution without grain deformation.

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36

Luo, Lei, Zhiyi Liu, Song Bai, Juangang Zhao, Diping Zeng, Jian Wang, Jing Cao, and Yangcheng Hu. "Hot Deformation Behavior Considering Strain Effects and Recrystallization Mechanism of an Al-Zn-Mg-Cu Alloy." Materials 13, no. 7 (April 9, 2020): 1743. http://dx.doi.org/10.3390/ma13071743.

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The hot deformation behavior of an Al-Zn-Mg-Cu alloy was investigated by hot compression test at deformation temperatures varying from 320 to 440 °C with strain rates ranging from 0.01 to 10 s−1. The results show that the Mg(Zn, Cu)2 particles as a result of the sufficient static precipitation prior to hot compression have an influence on flow softening. A constitutive model compensated with strain was developed from the experimental results, and it proved to be accurate for predicting the hot deformation behavior. Processing maps at various strains were established. The microstructural evolution demonstrates that the dominant dynamic softening mechanism stems from dynamic recovery (DRV) and partial dynamic recrystallization (DRX). The recrystallization mechanism is continuous dynamic recrystallization (CDRX). The microstructure observations are in good agreement with the results of processing maps. On account of the processing map and microstructural observation, the optimal hot processing parameters at a strain of 0.6 are at deformation temperature range of 390–440 °C and strain rate range of 0.010–0.316 s−1 with a peak efficiency of 0.390.

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37

Liao, Bin, Lingfei Cao, Xiaodong Wu, Yan Zou, Guangjie Huang, Paul Rometsch, Malcolm Couper, and Qing Liu. "Effect of Heat Treatment Condition on the Flow Behavior and Recrystallization Mechanisms of Aluminum Alloy 7055." Materials 12, no. 2 (January 20, 2019): 311. http://dx.doi.org/10.3390/ma12020311.

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The flow behavior and the microstructural evolution of aluminum alloy 7055 in two heat treatment conditions (homogenized vs. pre-rolled, solution treated, stretched and naturally aged (T3)) were investigated for a height reduction of 60% with deformation temperatures ranging from 370 °C to 450 °C and strain rates ranging from 0.01 s−1 to 10 s−1. Flow stress decline ratio maps as a function of deformation temperature and strain rate were produced along with processing maps at a strain of 0.8 to reveal optimum hot-working conditions for deformation at strain rates of 0.01 s−1 to 0.1 s−1. The results showed that the stress drop ratio during deformation is higher for the homogenized condition than for the pre-rolled, T3 condition. A higher degree of recrystallization after deformation was observed in the pre-rolled, T3 condition due to finer second phase particles, smaller grain size, and more numerous sub-grains. The mechanism for deformation softening is discussed in the context of grain boundary characteristics.

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38

Lypchanskyi, Oleksandr, Tomasz Śleboda, Aneta Łukaszek-Sołek, Krystian Zyguła, and Marek Wojtaszek. "Application of the Strain Compensation Model and Processing Maps for Description of Hot Deformation Behavior of Metastable β Titanium Alloy." Materials 14, no. 8 (April 17, 2021): 2021. http://dx.doi.org/10.3390/ma14082021.

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The flow behavior of metastable β titanium alloy was investigated basing on isothermal hot compression tests performed on Gleeble 3800 thermomechanical simulator at near and above β transus temperatures. The flow stress curves were obtained for deformation temperature range of 800–1100 °C and strain rate range of 0.01–100 s−1. The strain compensated constitutive model was developed using the Arrhenius-type equation. The high correlation coefficient (R) as well as low average absolute relative error (AARE) between the experimental and the calculated data confirmed a high accuracy of the developed model. The dynamic material modeling in combination with the Prasad stability criterion made it possible to generate processing maps for the investigated processing temperature, strain and strain rate ranges. The high material flow stability under investigated deformation conditions was revealed. The microstructural analysis provided additional information regarding the flow behavior and predominant deformation mechanism. It was found that dynamic recovery (DRV) was the main mechanism operating during the deformation of the investigated β titanium alloy.

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39

Wang, Xiaoguo, Jian Qin, Hiromi Nagaumi, Ruirui Wu, and Qiushu Li. "The Effect of α-Al(MnCr)Si Dispersoids on Activation Energy and Workability of Al-Mg-Si-Cu Alloys during Hot Deformation." Advances in Materials Science and Engineering 2020 (May 20, 2020): 1–12. http://dx.doi.org/10.1155/2020/3471410.

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The hot deformation behaviors of homogenized direct-chill (DC) casting 6061 aluminum alloys and Mn/Cr-containing aluminum alloys denoted as WQ1 were studied systematically by uniaxial compression tests at various deformation temperatures and strain rates. Hot deformation behavior of WQ1 alloy was remarkably changed compared to that of 6061 alloy with the presence of α-Al(MnCr)Si dispersoids. The hyperbolic-sine constitutive equation was employed to determine the materials constants and activation energies of both studied alloys. The evolution of the activation energies of two alloys was investigated on a revised Sellars’ constitutive equation. The processing maps and activation energy maps of both alloys were also constructed to reveal deformation stable domains and optimize deformation parameters, respectively. Under the influence of α dispersoids, WQ1 alloy presented a higher activation energy, around 40 kJ/mol greater than 6061 alloy’s at the same deformation conditions. Dynamic recrystallization (DRX) is main dynamic softening mechanism in safe processing domain of 6061 alloy, while dynamic recovery (DRV) was main dynamic softening mechanism in WQ1 alloy due to pinning effect of α-Al(MnCr)Si dispersoids. α dispersoids can not only resist DRX but also increase power required for deformation of WQ1 alloy. The microstructure analysis revealed that the flow instability was attributed to the void formation and intermetallic cracking during hot deformation of both alloys.

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Guo, Yuhang, Yaodong Xuanyuan, Chunnan Lia, and Sen Yang. "Characterization of Hot Deformation Behavior and Processing Maps of Mg-3Sn-2Al-1Zn-5Li Magnesium Alloy." Metals 9, no. 12 (November 26, 2019): 1262. http://dx.doi.org/10.3390/met9121262.

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The dynamic microstructure evolution of Mg-3Sn-2Al-1Zn-5Li magnesium alloy during hot deformation is studied by hot compression tests over the temperature range of 200–350 °C under the strain rate of 0.001–1 s−1, whereafter constitutive equations and processing maps are developed and constructed. In most of cases, the material shows typical dynamic recrystallization (DRX) features, with a signal peak value followed by a gradual decrease. The value of Q (deformation activation energy) is 138.89414 kJ/mol, and the instability domains occur at high strain rate but the stability domains are opposite, and the optimum hot working parameter for the studied alloy is determined to be 350 °C/0.001 s−1 according to the processing maps. Within 200–350 °C, the operating mechanism of dynamic recrystallization (DRX) of Mg-3Sn-2Al-1Zn-5Li alloy during hot deformation is mainly affected by strain rate. Dynamic recrystallization (DRX) structures are observed from the samples at 300 °C/0.001 s−1 and 350 °C/0.001 s−1, which consist of continuous DRX (CDRX) and discontinuous DRX (DDRX). However, dynamic recovery (DRV) still dominates the softening mechanism. At the grain boundaries, mass dislocation pile-ups and dislocation tangle provide sites for potential nucleation. Meanwhile, flow localization bands are observed from the samples at 200 °C/1 s−1 and 250 °C/0.1 s−1 as the main instability mechanism.

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41

Nie, Kaibo, Zhihao Zhu, Kunkun Deng, Ting Wang, and Jungang Han. "Hot Deformation Behavior and Processing Maps of SiC Nanoparticles and Second Phase Synergistically Reinforced Magnesium Matrix Composites." Nanomaterials 9, no. 1 (January 3, 2019): 57. http://dx.doi.org/10.3390/nano9010057.

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Magnesium matrix composites synergistically reinforced by SiC nanoparticles and second phases were prepared by 12 passes of multi-pass forging, varying the temperature. The effects of grain refinement and the precipitates on the hot deformation behavior were analyzed. Deformation zones which could be observed in the fine-grained nanocomposite before hot compression disappeared, and the trend of streamlined distribution for the precipitated phases was weakened. At the same compression rate, as the compression temperature increased, the number of precipitated phases decreased, and the grain size increased. For fine-grained nanocomposites, after the peak stress, there was no obvious dynamic softening stage on the stress–strain curve, and then the steady stage was quickly reached. The critical stress of the fine-grained nanocomposites was lower than that of the coarse-grained nanocomposites, which can be attributed to the large amounts of precipitates and significantly refined grains. The deformation mechanism of the coarse-grained nanocomposite was controlled by dislocation climb resulting from lattice diffusion, while the deformation mechanism for the fine-grained nanocomposite was dislocation climb resulting from grain boundary slip. The activation energy of the fine-grained nanocomposite was decreased, compared with the coarse-grained nanocomposite. The area of the workability region for the fine-grained nanocomposite was significantly larger than that of the coarse-grained nanocomposite, and there was no instability region at a low strain rate (0.001–0.01 s−1) under all deformation temperatures. The optimal workability region was 573 K /0.001–0.01 s−1 for the fine-grained nanocomposite, and the processing temperature was lower than the coarse-grained nanocomposite (623–673 K).

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Chen, Liquan, Chaoying Zhao, Ya Kang, Hengyi Chen, Chengsheng Yang, Bin Li, Yuanyuan Liu, and Aiguo Xing. "Pre-Event Deformation and Failure Mechanism Analysis of the Pusa Landslide, China with Multi-Sensor SAR Imagery." Remote Sensing 12, no. 5 (March 6, 2020): 856. http://dx.doi.org/10.3390/rs12050856.

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The Pusa landslide, in Guizhou, China, occurred on 28 August 2017, caused 26 deaths with 9 missing. However, few studies about the pre-event surface deformation are provided because of the complex landslide formation and failure mechanism. To retrieve the precursory signal of this landslide, we recovered pre-event deformation with multi-sensor synthetic aperture radar (SAR) imagery. First, we delineated the boundary and source area of the Pusa landslide based on the coherence and SAR intensity maps. Second, we detected the line-of-sight (LOS) deformation rate and time series before the Pusa landslide with ALOS/PALSAR-2 and Sentinel-1A/B SAR imagery data, where we found that the onset of the deformation is four months before landslide event. Finally, we conceptualized the failure mechanism of the Pusa landslide as the joint effects of rainfall and mining activity. This research provides new insights into the failure mechanism and early warning of rock avalanches.

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Kim, W. J., S. W. Chung, C. S. Chung, and D. Kum. "Superplasticity in thin magnesium alloy sheets and deformation mechanism maps for magnesium alloys at elevated temperatures." Acta Materialia 49, no. 16 (September 2001): 3337–45. http://dx.doi.org/10.1016/s1359-6454(01)00008-8.

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Kim, Su Hyeon, Jung Moo Lee, Young Hee Cho, Yeong Hwa Kim, and Hwa Jung Kim. "Hot Working and Processing Maps of TiC_p Reinforced Aluminum Alloy Matrix Composite." Key Engineering Materials 535-536 (January 2013): 296–99. http://dx.doi.org/10.4028/www.scientific.net/kem.535-536.296.

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Hot working behavior of an aluminum alloy matrix composite reinforced with TiC particulates was investigated by a high temperature compression test. Power dissipation maps were constructed using a dynamic material model and the deformation mechanism was investigated by means of an EBSD analysis. The interrelationship between the microstructure evolution and the efficiency of power dissipation was derived and the roles of TiC particles and other constituent phases in determining processing maps were further discussed.

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Viernstein, Bernhard, and Ernst Kozeschnik. "Integrated Physical-Constitutive Computational Framework for Plastic Deformation Modeling." Metals 10, no. 7 (June 30, 2020): 869. http://dx.doi.org/10.3390/met10070869.

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An integrated framework for deformation modeling has been developed, which combines a physical state parameter-based formulation for microstructure evolution during plastic deformation processes with constitutive creep models of polycrystalline materials. The implementations of power law, Coble, Nabarro–Herring and Harper–Dorn creep and grain boundary sliding are described and their contributions to the entire stress response at a virtual applied strain rate are discussed. The present framework simultaneously allows calculating the plastic deformation under prescribed strain rate or constant stress, as well as stress relaxation after preceding stress or strain loading. The framework is successfully applied for the construction of deformation mechanism maps.

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Liu, Guangming, Jinbin Wang, Yafeng Ji, Runyuan Hao, Huaying Li, Yugui Li, and Zhengyi Jiang. "Hot Deformation Behavior and Microstructure Evolution of Fe–5Mn–3Al–0.1C High-Strength Lightweight Steel for Automobiles." Materials 14, no. 10 (May 11, 2021): 2478. http://dx.doi.org/10.3390/ma14102478.

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The hot deformation behavior of a newly designed Fe–5Mn–3Al–0.1C (wt.%) medium manganese steel was investigated using hot compression tests in the temperature range of 900 to 1150 °C, at constant strain rates of 0.1, 1, 2.5, 5, 10, and 20 s−1. A detailed analysis of the hot deformation parameters, focusing on the flow behavior, hot processing map, dynamic recrystallization (DRX) critical stress, and nucleation mechanism, was undertaken to understand the hot rolling process of the newly designed steel. The flow behavior is sensitive to deformation parameters, and the Zener–Hollomon parameter was coupled with the temperature and strain rate. Three-dimensional processing maps were developed considering the effect of strain and were used to determine safe and unsafe deformation conditions in association with the microstructural evolution. In the deformation condition, the microstructure of the steel consisted of δ-ferrite and austenite; in addition, there was a formation of DRX grains within the δ-ferrite grains and austenite grains during the hot compression test. The microstructure evolution and two types of DRX nucleation mechanisms were identified; it was observed that discontinuous dynamic recrystallization (DDRX) is the primary nucleation mechanism of austenite, while continuous dynamic recrystallization (CDRX) is the primary nucleation mechanism of δ-ferrite. The steel possesses unfavorable toughness at the deformation temperature of 900 °C, which is mainly due to the presence of coarse κ-carbides along grain boundaries, as well as the lower strengthening effect of grain boundaries. This study identified a relatively ideal hot processing region for the steel. Further exploration of hot roll tests will follow in the future.

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Josell, D., T. P. Weihs, and H. Gao. "Diffusional Creep: Stresses and Strain Rates in Thin Films and Multilayers." MRS Bulletin 27, no. 1 (January 2002): 39–44. http://dx.doi.org/10.1557/mrs2002.18.

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AbstractIn this article, we discuss creep deformation as it relates to thin films and multilayer foils. We begin by reviewing experimental techniques for studying creep deformation in thin-film geometries, listing the pros and cons of each; then we discuss the use of deformation-mechanism maps for recording and understanding observed creep behavior. We include a number of cautionary remarks regarding the impact of microstructural stability, zero-creep stresses, and transient-creep strains on stress–strain rate relationships, and we finish by reviewing the current state of knowledge for creep deformation in thin films. This includes both thin films that are heated on substrates as well as multilayer films that are tested as freestanding foils.

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Thouless, M. D., J. Gupta, and J. M. E. Harper. "Stress development and relaxation in copper films during thermal cycling." Journal of Materials Research 8, no. 8 (August 1993): 1845–52. http://dx.doi.org/10.1557/jmr.1993.1845.

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The reliability of integrated-circuit wiring depends strongly on the development and relaxation of stresses that promote void and hillock formation. In this paper an analysis based on existing models of creep is presented that predicts the stresses developed in thin blanket films of copper on Si wafers subjected to thermal cycling. The results are portrayed on deformation-mechanism maps that identify the dominant mechanisms expected to operate during thermal cycling. These predictions are compared with temperature-ramped and isothermal stress measurements for a 1 μm-thick sputtered Cu film in the temperature range 25–450 °C. The models successfully predict both the rate of stress relaxation when the film is held at a constant temperature and the stress-temperature hysteresis generated during thermal cycling. For 1 μm-thick Cu films cycled in the temperature range 25–450 °C, the deformation maps indicate that grain-boundary diffusion controls the stress relief at higher temperatures (>300 °C) when only a low stress can be sustained in the films, power-law creep is important at intermediate temperatures and determines the maximum compressive stress, and that if yield by dislocation glide (low-temperature plasticity) occurs, it will do so only at the lowest temperatures (<100 °C). This last mechanism did not appear to be operating in the film studied for this project.

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Davydok, Anton, Thomas Cornelius, Zhe Ren, Cedric Leclere, Gilbert Chahine, Tobias Schülli, Florian Lauraux, Gunther Richter, and Olivier Thomas. "In Situ Coherent X-ray Diffraction during Three-Point Bending of a Au Nanowire: Visualization and Quantification." Quantum Beam Science 2, no. 4 (November 13, 2018): 24. http://dx.doi.org/10.3390/qubs2040024.

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The three-point bending behavior of a single Au nanowire deformed by an atomic force microscope was monitored by coherent X-ray diffraction using a sub-micrometer sized hard X-ray beam. Three-dimensional reciprocal-space maps were recorded before and after deformation by standard rocking curves and were measured by scanning the energy of the incident X-ray beam during deformation at different loading stages. The mechanical behavior of the nanowire was visualized in reciprocal space and a complex deformation mechanism is described. In addition to the expected bending of the nanowire, torsion was detected. Bending and torsion angles were quantified from the high-resolution diffraction data.

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Lin, Guo Qing. "Characterization of Hot Deformation Behavior of Zr-4 Alloy in Material Application Area." Advanced Materials Research 578 (October 2012): 202–5. http://dx.doi.org/10.4028/www.scientific.net/amr.578.202.

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The hot deformation behavior of Zr-4 alloy was studied in the temperature range 650-900°C and strain rate range 0.005-50s-1 using processing maps. The processing maps revealed three domains: the first occurs in the temperature range 780-820°C and strain rate range 0.005-0.05s-1, and has a peak efficiency of 45% at 790°C and 0.005s-1; the mechanism is the dynamic recrystallization. The second occurs in the temperature range greater than 900°C and strain rate range 0.05-0.8s-1, and has a peak efficiency of 40% at 900°C and 0.5s-1, which are the domains of dynamic recovery. In addition, the instability zones of flow behavior can also be recognized by the maps in the temperature range 650-780°C and strain rate range 0.01-0.1s-1, which should be strictly avoided in the processing of the material. Zr-4 alloy is the material for pressure tube applications in nuclear reactors and has better strength and a lower rate of hydrogen uptake compared to other materials under similar service conditions.

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Journal articles on the topic 'Deformation mechanism maps'

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