المؤلفون: Le Li, Zhenghao Chen, Seiko Tei, Yusuke Matsuo, Ryosuke Chiba, Koretaka Yuge, Haruyuki Inui, Easo P. George

المصدر: Science and Technology of Advanced Materials (2024)

مصطلحات موضوعية: High-entropy alloys, Single crystals, Critical resolved shear stress, Thermal activation, Mean-square atomic displacement, Materials of engineering and construction. Mechanics of materials, TA401-492, Biotechnology, TP248.13-248.65

الوصف: Temperature-dependent plastic deformation behaviors of single crystals of quaternary and ternary equiatomic medium-entropy alloys (MEAs) belonging to the Cr-Mn-Fe-Co-Ni system were investigated in compression at temperatures in the range 9 K to 1373 K. Their critical resolved shear stresses (CRSSs) increase with decreasing temperature below room temperature. There is also a dulling of the temperature dependence of CRSS below 77 K due to dislocation inertial effects that we attribute to a decrease in the phonon drag coefficient. These behaviors were compared with those of previously investigated single crystals of the equiatomic Cr-Co-Ni and Cr-Fe-Co-Ni MEAs, and the equiatomic Cr-Mn-Fe-Co-Ni high-entropy alloy (HEA). The temperature dependence of CRSS and the apparent activation volumes below room temperature can be well described by conventional thermal activation theories of face-centered cubic (FCC) alloys. Above 673 K, there is a small increase in CRSS, which we believe is due to elastic interactions between solutes and mobile dislocations, the so-called Portevin-Le Chatelier (PL) effect. The CRSS at 0 K was obtained by extrapolation of fitted CRSS vs. temperature curves and compared with predictions from solid solution strengthening models of HEA and MEAs.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1468-6996Test; https://doaj.org/toc/1878-5514Test

الوصول الحر: https://doaj.org/article/383acc1cfd9d47bfaabd62867d0a3cd3Test

المؤلفون: Lei Tian, Lifei Wang, Honghui Wu, Hongxia Wang, Liuwei Zheng, Kwang Seon Shin

المصدر: Journal of Materials Research and Technology, Vol 27, Iss , Pp 5572-5593 (2023)

مصطلحات موضوعية: Magnesium single crystal, Critical resolved shear stress, Deformation mode, Crystal plasticity finite element modeling, Corrosion, Mining engineering. Metallurgy, TN1-997

الوصف: Due to the hexagonal close-packed (HCP) crystal structure of Mg, the plasticity is poor at low temperatures. In order to solve this problem, the in-depth researches on various deformation modes of Mg are very necessary. However, there are many limitations to study these deformation modes in Mg polycrystals owing to the effect of grain boundaries, etc. It is more reasonable to conduct the researches in Mg single crystals, especially investigating the influence of crystal orientations, and the advantages of Mg single crystals are prominent particularly. On this basis, various investigations in Mg single crystals are carried out thoroughly in recent years, such as the critical resolved shear stress (CRSS) calculation, the slip and twinning modes activation determining, recrystallization behaviors and so on. In order to make clear the research advantages in Mg single crystals, a critical brief summary is conducted in this paper. Besides, various crystal plasticity finite element modeling (CPFEM) and electrochemical corrosion used in Mg single crystals are also reviewed. Finally, the current challenges and possible research directions are proposed.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2238785423027217Test; https://doaj.org/toc/2238-7854Test

الوصول الحر: https://doaj.org/article/cded88d5f30f45448b5edcbd0057eee7Test

المؤلفون: Wencong Zhang, Jinqi Pan, Songhui Wang, Jianlei Yang

المصدر: Journal of Materials Research and Technology, Vol 27, Iss , Pp 3041-3053 (2023)

مصطلحات موضوعية: Plane strain compression, Dynamic recrystallization, Critical resolved shear stress, Deformation mechanism, Mining engineering. Metallurgy, TN1-997

الوصف: A series of hot plane strain compression (PSC) experiments of the extruded Mg-6.03Zn-0.55Zr alloy were conducted on the Gleeble-3500 machine with strain rates of 0.01 s−1 to 10 s−1 and temperatures ranging from 300 °C to 500 °C to reveal the microstructure evolution during the secondary process. The effects of grain refinement and texture modification which were easily affected by the deformation mechanism and dynamic recrystallization (DRX) were systematically studied. Experimental results showed that the main deformation mechanism during PSC was basal slip (74.3 %–94.9 %) and assisted by prismatic slip (4.8 %–21.1 %) and pyramidal slip (0.3 %–4.6 %). Since the pyramidal slip and prismatic slip were more preferred to activate owing to the significant decrease of critical resolved shear stress (CRSS) at a higher temperature, the activation of non-basal slip promoted the c-axes of the grains deviated from compression direction which weakened the basal fiber texture. Moreover, the activation of non-basal slip could promote DRX behavior to some extent. Further analysis of the DRX mechanism showed that the continuous DRX (CDRX) by continuous rotation of low angle grain boundaries was dominant at lower temperatures and higher strain rates, while discontinuous DRX (DDRX) which nucleated at the grain boundaries played a more and more important role as the temperature increased and strain rate decreased. After characterizing the orientations of the DRXed grains, the CDRXed grains owned a similar grain orientation with the deformed grain while the DDRXed grains exhibited a fairly dispersed distribution, indicating that the weakening effect of the basal texture was greater with a higher DDRX fraction.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2238785423025619Test; https://doaj.org/toc/2238-7854Test

الوصول الحر: https://doaj.org/article/3bb03bdce36d4201b1c06719836c0b7bTest

المؤلفون: Tongfei Zou, Meng Liu, Quanyi Wang, Yunqing Jiang, Hao Wu, Zhenhuan Gao, Yubing Pei, Hong Zhang, Yongjie Liu, Qingyuan Wang

المصدر: Materials & Design, Vol 239, Iss , Pp 112795- (2024)

مصطلحات موضوعية: Nickel-based superalloy, Deformation mechanism, Microstructure, Critical resolved shear stress, Materials of engineering and construction. Mechanics of materials, TA401-492

الوصف: Tensile interruption experiments with different strains were conducted on additively fabricated nickel-based Inconel 939 superalloys at 700 ℃ to investigate the evolution of multiple deformation mechanisms. The microstructures of different strain groups captured by transmission electron microscopy (TEM) were analyzed, and it was concluded that a total of four various deformation mechanisms were identified, of which the first to be activated was the Orowan loop bypassing γ', and a tendency of transition from double to single loop was observed. Anti-phase boundary (APB) shearing was subsequently initiated, with a needed critical resolved shear stress level of approximately 195.82 MPa. Stacking faults (SFs) and deformation twinnings (DTs) were observed at higher stress, accompanied by the dissociation of dislocations. In addition, the magnitude of the stacking fault energy of AM 939 superalloys at intermediate temperature was calculated and estimated by matching the experimental phenomena with the critical shear stress.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0264127524001679Test; https://doaj.org/toc/0264-1275Test

الوصول الحر: https://doaj.org/article/f2aa17b8021944eeaca56b580dfa624fTest

المؤلفون: Zhao, Z, To, S, Wang, J

المساهمون: Department of Industrial and Systems Engineering

مصطلحات موضوعية: Commercial pure titanium (CP Ti), Critical resolved shear stress (CRSS), Grains and deformation twins, Microcracks, Ultraprecision diamond turning

الوصف: 202402 bcch ; Accepted Manuscript ; Others ; The Hong Kong Polytechnic University; State Key Laboratory of Ultra-precision Machining Technology ; Published ; Green (AAM)

العلاقة: http://hdl.handle.net/10397/104207Test; 10; 22; 271; 2-s2.0-85063209939; ISE-0433

الإتاحة: https://doi.org/10.1016/j.jmatprotec.2019.03.018Test
http://hdl.handle.net/10397/104207Test

المؤلفون: Xue-Chun Zhang, Shuo Cao, Lian-Ji Zhang, Rui Yang, Qing-Miao Hu

المصدر: Journal of Materials Research and Technology, Vol 22, Iss , Pp 3413-3422 (2023)

مصطلحات موضوعية: First-principles method, Generalized stacking fault energy, Semi-discrete variational peierls-nabarro model, Critical resolved shear stress, Mining engineering. Metallurgy, TN1-997

الوصف: Determining the competition between the {110}⟨111⟩, {112}⟨111⟩ and {123}⟨111⟩ slip systems in body-centered cubic (BCC) metals is important to understand their mechanical properties. In this paper, the unstable stacking fault energy (γus) and Peierls stress (σp) of the three slip systems of a series of BCC metals are calculated in order to evaluate the competition among them. We find that γus of BCC metals is proportional to (B+G)/a2/3, where B, G and a are the bulk modulus, shear modulus and lattice constant, respectively. The calculations of γuss predict that the {110}⟨111⟩ dislocation slip is prior to the {112}⟨111⟩ and {123}⟨111⟩ slips, however, γus may not be used to identify the priorities of the latter two slips because γuss of these two slip systems are too close to each other. According to σps, the mobility of dislocations decreases in the sequence of {110}⟨111⟩, {112}⟨111⟩, {123}⟨111⟩ for all the metals considered except for K. Noticeably, it is shown that γus and σp are not monotonically related to each other.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2238785422020440Test; https://doaj.org/toc/2238-7854Test

الوصول الحر: https://doaj.org/article/faf2bb52cc2d492fa9e8a700ad9115f4Test

المؤلفون: Akihiro SATO, Tomohiro TAKEDA, Yoshiki KAWANO

المصدر: Nihon Kikai Gakkai ronbunshu, Vol 89, Iss 923, Pp 23-00084-23-00084 (2023)

مصطلحات موضوعية: critical resolved shear stress, normalized schmid factor, crystal plasticity analysis, hexiagonal close-packed structure, prediction, Mechanical engineering and machinery, TJ1-1570, Engineering machinery, tools, and implements, TA213-215

الوصف: Critical resolved shear stress (CRSS) determines the ease of slip deformation of metals. In crystal structures with low symmetry, such as the HCP structure, non-equivalent slip systems exist. CRSSs are different between the non-equivalent slip systems. The CRSS ratios between slip systems is an important factor governing the plastic deformation mechanism. Thus, methods for easily evaluating the CRSS ratios will play an important role to understand the deformation mechanism. In this study, we developed and validated a system to predict CRSS ratios for metal materials using spatial distributions of normal strain in the tensile direction and crystal orientation. The validation was performed by predicting CRSS ratios of HCP metals using the strain distributions which was obtained by crystal plasticity finite element analysis (CPFEM). The results showed that CRSS ratios were successfully predicted under conditions where multiple slip systems were activated, but in some cases the prediction failed. Investigating the cause of failure, we found that predictions failed under the following conditions: (i) only one slip system was active, (ii) distributions of Schmid factor for individual slip systems were similar to each other, and (iii) multiple slip systems were activated in the same region. We also proposed methods to solve the problems.

وصف الملف: electronic resource

العلاقة: https://www.jstage.jst.go.jp/article/transjsme/89/923/89_23-00084/_pdf/-char/enTest; https://doaj.org/toc/2187-9761Test

الوصول الحر: https://doaj.org/article/41205530a09049ae8579c2a89805dcc1Test

المؤلفون: Wiktor Bednarczyk, Maria Wątroba, Manish Jain, Krzysztof Mech, Piotr Bazarnik, Piotr Bała, Johann Michler, Krzysztof Wieczerzak

المصدر: Materials & Design, Vol 229, Iss , Pp 111897- (2023)

مصطلحات موضوعية: Zinc alloys, Micro-pillar compression, Critical resolved shear stress, Solid-solution strengthening, Materials of engineering and construction. Mechanics of materials, TA401-492

الوصف: The room-temperature plastic deformation behavior of pure Zn and Zn-Ag (0–2.2 at.%) biodegradable alloys has been investigated via uniaxial in situ micro-pillar compression tests performed within a scanning electron microscope. The critical resolved shear stresses (CRSS) were quantified as a function of micro-pillar diameter. The compression of single crystal micro-pillars was performed at various strain rates in carefully selected grains, the crystallographic orientation of which facilitates deformation either via basal 0001〈112¯0〉 or prismatic 101¯0〈112¯0〉 slip. The CRSS values increased with decreased micro-pillar diameter, revealing a more pronounced size effect in pure Zn deformed via basal slip. The observed solid solution strengthening effect in Zn-Ag alloys with increasing Ag content was associated with a CRSS increase from 26.6 MPa to 37.0 MPa (by ∼ 40 %) in the basal slip system and from 99.1 MPa to 188.4 MPa (by ∼ 104 %) in the prismatic slip system. The extraordinarily high CRSS values for basal slip activated in pure Zn and Zn-0.14Ag alloy compared to the solid solution strengthening model was attributed to the critically low dislocation density. In the Zn-Ag alloy with Ag content > 0.5 at.% higher dislocation densities are expected, which result in a more predictable plastic deformation behavior.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S026412752300312XTest; https://doaj.org/toc/0264-1275Test

الوصول الحر: https://doaj.org/article/643c5c3c2b034f11a82d32f851b3d4d7Test

المؤلفون: Anand, Lallit, author, Kamrin, Ken, author, Govindjee, Sanjay, author

المصدر: Introduction to Mechanics of Solid Materials, 2022, ill.

الإتاحة: https://doi.org/10.1093/oso/9780192866073.003.0012Test

المؤلفون: Kot, P., Wroński, M., Baczmański, A., Ludwik, A., Wroński, S., Wierzbanowski, K., Scheffzük, Ch, Pilch, J., Farkas, G.

المصدر: Measurement: Journal of the International Measurement Confederation, 221, Art.Nr.: 113469 ; ISSN: 0263-2241, 1873-412X

مصطلحات موضوعية: Neutron diffraction measurement, Crystallographic slip, Twinning, Critical resolved shear stress, Elastoplastic deformation, Magnesium alloy, ddc:910, Geography & travel, info:eu-repo/classification/ddc/910

الوصف: A novel original method of determination of stresses and critical resolved shear stresses (CRSSs) using neutron diffraction was proposed. In this method, based on the crystallite group method, the lattice strains were measured in different directions and using different reflections hkl during uniaxial deformation of magnesium alloy AZ31. The advantage of this method is that the stresses for groups of grains having similar orientations can be determined directly from measurement without any models used for data interpretation. The obtained results are unambiguous and do not depend on the models assumptions as in previous works. Moreover, it was possible for the first time to determine the uncertainty of the measured CRSS values and local stresses at groups of grains. The used methodology allowed for the determination of stress partitioning between grains having different orientations and for an explanation of the anisotropic mechanical behaviour of the strongly textured alloy. Finally, the CRSS values allowed for the validation of the type of intergranular interaction assumed in the elastic–plastic self-consistent model and for a significant reduction of the number of unknown parameters when the model is adjusted to the experimental data.

وصف الملف: application/pdf

العلاقة: info:eu-repo/semantics/altIdentifier/wos/001081720000001; info:eu-repo/semantics/altIdentifier/issn/0263-2241; info:eu-repo/semantics/altIdentifier/issn/1873-412X; https://publikationen.bibliothek.kit.edu/1000162625Test; https://publikationen.bibliothek.kit.edu/1000162625/151412033Test; https://doi.org/10.5445/IR/1000162625Test

الإتاحة: https://doi.org/10.5445/IR/1000162625Test
https://doi.org/10.1016/j.measurement.2023.113469Test
https://publikationen.bibliothek.kit.edu/1000162625Test
https://publikationen.bibliothek.kit.edu/1000162625/151412033Test