Article
Materials Science, Multidisciplinary
Zhuoliang Li, Hua Ding, Yi Huang, Terence G. Langdon
Summary: Pure Mg samples undergo high-pressure torsion (HPT) processing at temperatures of 293 and 423 K, resulting in significantly refined microstructures and bimodal structures at both temperatures. Tensile experiments reveal that the yield strength increases with increasing numbers of turns at 293 K, while it remains almost constant at 423 K. Pure Mg processed at 423 K exhibits higher strain hardening ability and larger uniform elongation compared to processing at 293 K. Grain size, bimodal structure, and dislocation density are identified as the main factors influencing material strength and work hardening behavior.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Zixuan Wu, Xiaosong Jiang, Yanjun Li, Pal Christian, Hongliang Sun, Yali Zhang, Yongjian Fang, Rui Shu
Summary: In this study, graphene nanoplatelets (GNPs) reinforced Cu/Ti3SiC2/C nanocomposites were successfully prepared by high-pressure torsion (HPT) after powder metallurgy. The study systematically analyzed the microstructures, interfacial bonding, mechanical, and electrical properties of the nanocomposites. The results showed that HPT significantly improved the dispersion of GNPs, the clarity and bonding of interfaces between the matrix and reinforcing phases. The grain size of the nanocomposites was considerably refined. The study also found that with the increase of HPT turns, the relative density, mechanical, and electrical properties of the nanocomposites were all improved.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Ying Chen, Xu Yuan, Jiahui Dong, Shenbao Jin, Gang Sha, Yihang Yang, Houan Zhang, Chuanting Wang, Nong Gao, Marco J. Starink
Summary: In this study, we successfully increased the tensile strength and ductility of AA6xxx series aluminum alloy through high-pressure torsion (HPT) processing. Analysis by X-ray diffraction and transmission electron microscopy revealed the formation of a high density of dislocations and a decrease in grain size. Atom probe tomography showed strong solute segregation on ultrafine-grained boundaries. It was found that solute segregation at dislocations and on grain boundaries is the dominant strengthening mechanism in the HPT processed 6xxx series Al-Mg-Si alloy.
MATERIALS CHARACTERIZATION
(2023)
Article
Nanoscience & Nanotechnology
Qian He, Shuhei Yoshida, Nobuhiro Tsuji
Summary: This study reports the characteristic strengthening mechanisms of HfNbTaTi, HfNbTiZr, HfNbTi, HfTaTi, and NbTiZr equi-atomic refractory medium entropy alloys (RMEAs). The alloys were processed to obtain microstructures with varying grain sizes and their mechanical properties were evaluated. The low elastic modulus of the RMEAs was found to be the reason for their small slopes of the Hall-Petch relationships and weak grain refinement strengthening. Moreover, the high friction stresses of the RMEAs were attributed to the interaction between severe lattice distortion and elastic field of edge dislocations.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Min-Seok Baek, Abdul Wahid Shah, Young-Kyun Kim, Shae-K. Kim, Bong-Hwan Kim, Kee-Ahn Lee
Summary: This study investigated the microstructures, mechanical properties, tensile deformations, and strengthening mechanisms of Al-Mg alloys with different Mg contents. Higher Mg content resulted in higher fractions of C15 phases and increased yield strengths. The 9Mg alloy exhibited better resistance to serrated flow due to its fine equiaxed grains and higher Mg content and number densities of obstacles. Solid-solution and grain-boundary strengthening contributed to the overall yield strength. The study demonstrated the potential of conventional models to accurately predict the yield strengths of Al-Mg alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Tianyu Guo, Zhangmin Wan, Yan Yu, Hui Chen, Zhifeng Wang, Dagang Li, Junlong Song, Orlando J. Rojas, Yongcan Jin
Summary: This study investigates the mechanism of binding between dopamine-conjugated carboxymethyl cellulose and carbon nanotubes, as well as the strain-induced interfacial strengthening in wet-spun filaments. The results reveal the reversible torsion of neighboring molecules and the wrapping of DA-CMC around CNTs as the main factors contributing to the interfacial strengthening of the filaments. These findings are significant for the development and improvement of high-performance fibers.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Qianqian Fu, Bing Li, Hongwang Fu, Minqiang Gao, Changfeng Wang, Ying Fu, Renguo Guan
Summary: This study systematically investigates the cryogenic and room temperature drawing behaviors of Cu-Te alloy. It finds that the liquid nitrogen temperature drawn Cu-Te alloy has higher yield strength and ultimate tensile strength, and promotes the formation of deformation twinning and shear bands.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
Harishchandra Lanjewar, Leo A. I. Kestens, Patricia Verleysen
Summary: In this study, an in-depth analysis of the elastoplastic behavior of commercially pure aluminum pre-strained via severe plastic deformation (SPD) and tested in tension was conducted. The microstructures of the tensile samples were found to be influenced by the different stages of treatment, with dislocation strengthening playing a significant role in the fragmentation stage and grain boundary strengthening dominating in the steady-state stage. The evolution of dislocation density was shown to have a prominent effect on material strength and deformation behavior, with potential implications for improving mechanical properties in pre-strained materials.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Furong Cao, Xiaoming Teng, Ruikang Su, Jinrui Liang, Renjie Liu, Shuting Kong, Nanpan Guo
Summary: A novel Al-3.25Mg-0.37Zr0.28Mn-0.19Y (wt.%) alloy with improved ambient strength and high temperature ductility was fabricated using multidirectional forging and warm rolling. The alloy exhibited high ultimate tensile strength, yield strength, and elongation at room temperature, and demonstrated maximum superplasticity at elevated temperatures. The strengthening mechanisms in the alloy included grain boundary strengthening, dislocation strengthening, Orowan strengthening, and solid solution strengthening. The occurrence of Portevin-Le Chatelier effect or serrated flow was observed in the alloy, and constitutive equations were established to describe its behavior.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Nanoscience & Nanotechnology
Xicong Ye, Zihao Cheng, Chang Liu, Xin Wu, Luer Yu, Mengyu Liu, Dong Fang, Guangwei Zhao, Bo Li
Summary: The emergence of eutectic high entropy alloys (EHEAs) has led to the design and preparation of a set of low-cost Co-free Fe55Cr15Ni(30-x)Nbx (x = 0, 3, 6, 9, 12, and 15 at.%) EHEAs in this study. The addition of Nb content affects the solidification structure and mechanical properties of the alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Kevin Jacob, Deepesh Yadav, Saurabh Dixit, Anton Hohenwarter, Balila Nagamani Jaya
Summary: Maraging steels were processed using High Pressure Torsion (HPT) to improve aging kinetics and hardness. The particles changed from spherical to plate like form in overaged conditions. A 70% increase in ultimate tensile strength was achieved in HPT processed samples.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Crystallography
Jintao Zhang, Shibo Wang, Hua Ding, Peng Hu, Yi Huang, Yu Zhang
Summary: In this study, high-pressure torsion (HPT) was used to process Ni49.6Ti35.4Hf15 alloy with 1/4, 2 and 16 turns under a pressure of 4.0 GPa. The results showed that a mixture of amorphous and nanocrystalline microstructure developed in the alloy with increased HPT turns. The hardness of the samples increased significantly after 16 turns of HPT. Annealing of the HPT-processed samples at 550°C resulted in the formation of very fine martensite, with finer microstructures obtained with higher HPT turns. Differential scanning calorimetry (DSC) tests confirmed the transformation behavior after severe plastic deformation and annealing, providing experimental basis for the application of shape memory alloy.
Article
Materials Science, Multidisciplinary
Jun Chen, Jia-kuan Ren, Zhen-yu Liu
Summary: Al addition in high Mn steels leads to solid-solution strengthening and grain refinement, but formation of delta-ferrite at 8.0wt% Al content results in brittleness. The major deformation mechanisms change with increasing Al content, impacting the total elongation and impact properties of the steels.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Materials Science, Multidisciplinary
B. Sadeghi, P. Cavaliere, Catalin Iulian Pruncu
Summary: An architecture-based model is proposed to reveal the correlations between the architecture and strengthening mechanisms of Graphene/ aluminum (GR/Al) composites with heterogeneous lamellar (HL) architecture. The model describes the role of HL design factors in influencing the microstructural architecture and strengthening mechanisms of the material. The optimal alignment of structural elements and graphene leads to a combined effect of isotropic and kinematic strain hardening, as well as higher levels of back stress and back stress hardening.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
V. Tavakkoli, A. Mazilkin, T. Scherer, M. Mail, Y. Beygelzimer, B. Baretzky, Y. Estrin, R. Kulagin
Summary: In the study, it was found that during high-pressure torsion, the molybdenum layer loses planarity, leading to periodic folds and vortices, causing ruptures; a blocky substructure was formed in the molybdenum layer, while a significant fragmentation of the copper layer occurred; the proposed mathematical model, based on gradient plasticity theory, predicted the instability of the harder molybdenum layer.
Article
Polymer Science
Jorge S. S. Neto, Henrique F. M. de Queiroz, Daniel K. K. Cavalcanti, Ricardo A. A. Aguiar, Antonio B. Pereira, Mariana Doina Banea
Summary: The study revealed that aging process affects the mechanical properties of different types of composites in various ways. The properties of jute and hybrid jute/glass composites decreased with increased exposure time, while the hybrid composites with MWCNTs showed improvements in certain aspects.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Engineering, Manufacturing
Toshihiko Kuwabara, Ren Tachibana, Yusuke Takada, Takayuki Koizumi, Sam Coppieters, Frederic Barlat
Summary: This study experimentally investigates the effect of hydrostatic stress on the strength differential effect (SDE) in a low-carbon steel sheet. The results show a positive correlation between hydrostatic pressure and flow stress, leading to the occurrence of SDE.
INTERNATIONAL JOURNAL OF MATERIAL FORMING
(2022)
Article
Materials Science, Multidisciplinary
Rafael O. Santos, Luciano P. Moreira, Marilena C. Butuc, Gabriela Vincze, Antonio B. Pereira
Summary: This study evaluated the third generation of advanced high-strength steels (AHSS) through various analyses and tests. The results showed that the CR980XG3(TM) steel has good overall formability and weak plastic anisotropy.
Article
Engineering, Mechanical
Jianwei Zhao, Quan Yang, Hossein Eskandari Sabzi, Wei Wen, Pedro E. J. Rivera-Diaz-del-Castillo
Summary: Stress relaxation after hot deformation is modeled by considering various physical phenomena, including dislocation recovery, recrystallization, and precipitation. The model incorporates new formulations, such as a vacancy-mediated dislocation climb approach for dislocation recovery. The softening behavior of 6 microalloyed steel grades is tracked and compared with experimental data. The approach is also discussed for its application in additive manufacturing microstructural relaxation.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Mechanics
Marco Rossi, Attilio Lattanzi, Frederic Barlat, Jin-Hwan Kim
Summary: The hydraulic bulge test (HBT) is an important experimental technique to identify the properties of materials, particularly metals. This paper proposes a new approach using stereo-DIC to obtain the displacement field and apply it in an inverse identification scheme for evaluating the properties of metals.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Industrial
Seong-Yong Yoon, Frederic Barlat, Shin-Yeong Lee, Jin-Hwan Kim, Min-Su Wi, Dong-Jin Kim
Summary: In this study, the hydrostatic pressure-dependency of the distortional plasticity model HAH(20) was implemented using a finite element code to account for the strength-differential effect observed in high-strength steel sheets. The implementation was validated by comparing the results with a stand-alone code and experimental data, and the influence of the strength-differential effect on springback simulation was analyzed.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Chemistry, Physical
Fabio A. O. Fernandes, Jose P. Pinto, Bruno Vilarinho, Antonio B. Pereira
Summary: This study focuses on the dissimilar joining between polymethylmethacrylate (PMMA) and S235 galvanised steel using a pulsed Nd:YAG laser. The influence of processing parameters and surface conditions on joint strength and quality are investigated. The study reveals the optimum process parameters and the possibility of enhancing joint strength through mechanical pre-treatment.
Review
Materials Science, Multidisciplinary
Eva S. Marques, Antonio B. Pereira, Francisco J. G. Silva
Summary: In order to reduce waste and undesirable costs, it is important to establish quality plans that ensure product conformity and address the root causes of welding defects. This study focused on dual phase (DP) steels, which are commonly used in the automotive industry, and developed a quality plan for laser welding DP steel components. The quality plan includes pre-welding, during and post-welding stages, and the mechanical properties of the welded components were also assessed. The findings suggest that DP steel has good weldability except for the softening of the heat affected zone (HAZ) and the growth of martensite in the fusion zone (FZ), and analysis techniques such as finite element method (FEM), visual techniques during welding, and digital image correlation (DIC) for post-weld analysis can help prevent failures.
Article
Engineering, Mechanical
Mooyeong Joo, Min-Su Wi, Seong-Yong Yoon, Shin-Yeong Lee, Frederic Barlat, Carlos N. Tome, Bohye Jeon, Youngung Jeong
Summary: An incremental elasto-visco-plastic self-consistent polycrystal model was directly interfaced with a finite element code to simulate the 3-point-bending process of a mild steel sample. This study predicts the springback response after various amounts of prestrains for the first time. The crystallographic orientation distribution obtained from an EBSD scan was used to assign the initial polycrystalline aggregate for each finite element integration point. The model successfully predicts the effect of prestrain on springback and can be directly applied to industrial forming and springback predictions.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
Seongyong Yoon, Frederic Barlat
Summary: A non-iterative stress update method is proposed to accelerate finite element simulations in plasticity. This method directly integrates the stress tensor based on elastoplastic constitutive law without needing a recursive root-finding process. The method ensures the positivity of the effective plastic strain increment and resolves the uncertainty of yield condition fulfillment through a stress projection technique. It significantly reduces computation time by approximately 50% while maintaining high accuracy in a variety of finite element simulation examples.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
Shin-Yeong Lee, Seong-Yong Yoon, Jin-Hwan Kim, Kyung-Seok Oh
Summary: This study assesses the performance of conventional and advanced constitutive models in predicting springback for ultra-high strength steel. The elasto-plastic behavior of a martensitic steel sheet sample is characterized to evaluate the conventional stress-strain behavior. Various tests, including uniaxial compression and tension-compression experiments, are conducted to assess the strength-differential effect and hardening fluctuations during non-linear loading paths. Three constitutive plasticity models are calibrated and employed for finite element predictions of springback. The HAH20 model, which considers both SD and NLLP effects, performs the best in predicting forming and springback for martensitic steel.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Chemistry, Physical
Giovani Lombardi, Margarida Pinho-Lopes, Antonio Miguel Paula, Antonio Bastos Pereira
Summary: A constitutive model was used to describe the tensile response of two woven PET geogrids, before and after mechanical damage. The model parameters of undamaged and damaged specimens were estimated via numerical regressions. Tensile load-strain curves of damaged samples were drawn by applying scaling factors to the plot of the undamaged sample. The model allowed us to describe the load-strain curve of a geogrid from its tensile properties and could be applied to both laboratory and in situ damaged samples.
Article
Chemistry, Physical
Mabrouka Akrout, Basma Ben Difallah, Mohamed Kharrat, Maher Dammak, Antonio Pereira, Filipe J. Oliveira, Isabel Duarte
Summary: The purpose of this study was to investigate the properties of novel polymer/metal composite materials for bearing applications. Copper-filled ABS composites were mixed and the dispersion of Cu particles in the matrix was studied. The study concluded that the incorporation of Cu filler improved the friction and wear properties of the composites, making them suitable for a wider range of mechanical components for bearing applications.
Article
Crystallography
Fabio A. O. Fernandes, Jose J. M. Goncalves, Antonio B. Pereira
Summary: This study investigates the laser weldability between dissimilar non-ferrous metallic materials and evaluates the quality of welds. The results show that the strength of the welded samples is close to the base material, but there are microporosities and cracks near the heat-affected zone.
Article
Engineering, Electrical & Electronic
Gabriela Vincze, Antonio B. Pereira, Diogo A. F. Lopes, Jesus M. Yanez, Marilena C. Butuc
Summary: Asymmetric rolling is a method to improve the performance of sheet metals. This study investigates the effect of asymmetric rolling on an aluminum alloy used in the automotive industry. The results show that all rolling conditions lead to increased strength and decreased formability. Adequate heat treatment after rolling can achieve a reasonable combination of high strength and acceptable formability.
