Article
Materials Science, Multidisciplinary
Hao Cheng, Yong-Cheng Lin, Dao-Guang He, Hong-Bin Li, Zi-Jian Chen, Jun-Cheng Zhu
Summary: The study investigated the hot deformation behavior and microstructure evolution of stress and stress-free aged Ni-Cr-Nb-Mo-Ti alloy through hot compressive tests. It was found that the basket-weave delta-phases refine grains during hot deformation, but significantly hinder the growth of DRX grains and lead to a substantial increase in peak stress. Dislocations pinned near the basket-weave delta-phases can hinder grain boundary migration and accelerate the DRX process during hot deformation.
ADVANCED ENGINEERING MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Kelvin Wong, Nicholas Armstrong
Summary: The complexity of collective dislocation behavior has led to the use of mesoscopic models, but there is no generally accepted method for transforming a deterministic model into a stochastic one. This study proposes a physically motivated method for deriving stochastic models that preserve the non-negativity of the dislocation density and ensure the desired physical bounds.
Review
Materials Science, Multidisciplinary
Tianli Zhao, Bing Zhang, Zhijuan Zhang, Le Chen, Yi Xu, Jun Cai, Kuaishe Wang
Summary: Pure Ti, as a component layer of layered composites, exhibits excellent properties such as high specific strength, low density, low elastic modulus, high-temperature corrosion resistance, and excellent biocompatibility. It shows good flow behavior and recrystallization characteristics during hot deformation studies.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Sumit Ghosh, Mahesh Chandra Somani, Daria Setman, Suhrit Mula
Summary: Efforts have been made to establish a relation between Zener-Hollomon parameter, flow stress, and dynamic recrystallization in Ti + Nb stabilized interstitial free (IF) steel. A novel constitutive model has been developed to predict the flow behavior in both alpha and gamma phase regions, showing high correlation coefficients and low average absolute relative errors with experimental data. The dominant mechanism for dynamic recrystallization appears to be dislocation glide controlled by dislocation climb.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Liang Wang, Botao Jiang, Xuan Wang, Ruirun Chen, Yingmei Tan, Liangshun Luo, Yanqing Su, Jingjie Guo
Summary: An advanced melt hydrogenation method was used to improve the poor hot workability of titanium matrix composites (TMCs). The (TiB+TiC)/Ti-6Al-4 V composites were fabricated by directly melting alloys in a gas mixture of H2 and Ar. The results showed that melt hydrogenation increased the length of TiB whiskers and aggravated the clustering of reinforcements, thereby improving the hot workability of TMCs in (' + beta) phase region. The formation of more dynamic recrystallization (DRX) grains and enhanced mobility of dislocations contributed to the improved hot workability.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Juan Liao, Lixia Zhang, Hongliang Xiang, Xin Xue
Summary: This study conducted ultrasonic vibration-assisted hot deformation experiments on AZ31 magnesium alloy sheets, revealing significant effects on mechanical properties and microstructural evolution, such as delayed occurrence of dynamic recrystallization and accelerated continuous dynamic recrystallization leading to improved material ductility.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Anna Wojtacha, Marek Opiela
Summary: This study investigated the effect of hot working conditions on changes in yield stress and the softening degree in the newly developed multiphase steel with Ti and V microadditions. The results provide insights for developing thermomechanical treatment technology for the production of forgings from the tested multiphase steel.
Article
Chemistry, Physical
Yechen Deng, Yixin An, Yangzhihong Xiao, Xiaodong Zhan, Xiaoyong Zhang, Bingfeng Wang
Summary: Controlling the hot deformation mechanism and avoiding deformation instability are crucial in hot forging of titanium alloy. A high throughput experimental method was used to efficiently establish a deformation mechanism map by deforming double-cone specimens. The results showed a continuously varying strain distribution from 0.3 to 1.4, with dynamic recovery and dynamic recrystallization as the dominant deformation mechanisms. The formation of deformation bands and the aggravation of microstructural nonuniformity within the Ti-55511 titanium alloy were identified as leading to deformation instability.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Qing Hu, Yan Wang, Liangxing Lv, Yaofeng Luo, Liang Su, Bin Liu
Summary: Hot processing is effective in optimizing the microstructure of gamma-TiAl alloy. This study investigates the hot deformation behavior and deformation mechanism of Ti-48Al-2Nb-2Cr alloy with near-gamma microstructure under different conditions. A constitutive model is established, and hot processing maps are constructed. The results demonstrate that dynamic recrystallization and dynamic recovery play significant roles in the softening mechanism of the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Aditya Sarkar, S. V. S. Narayana Murty, M. J. N. V. Prasad
Summary: Uniaxial and plane strain compression tests were conducted on Cu-Cr-Zr-Ti alloy specimens to examine the influence of deformation mode on stress-strain response, work hardening behavior, and microstructural evolution. The results showed that the alloy exhibited a transition from recovery stage to steady state under uniaxial compression, while a smooth transition was observed under plane strain compression. Additionally, the microstructures evolved differently under the two compression modes.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Fengbo Sun, Rui Zhang, Yu Zhang, Fanchao Meng, Zishuo Ma, Lujun Huang, Lin Geng
Summary: Titanium carbide based composites, renowned for their light weight, high elastic modulus, and exceptional wear resistance, face significant challenges in hot working, especially in terms of coordinated deformation of the brittle phase. This study introduced a soft Ti phase to enhance the thermal deformation ability and investigated the dynamic recrystallization mechanism, crack propagation, and dislocation motion behavior of the brittle Ti2C matrix. Through hot compression, the optimal processing temperature of 950 degrees C was determined, leading to microstructure refinement via discontinuous and continuous dynamic recrystallization. The intergranular Ti phase acted as a binder, facilitating deformation coordination and mitigating stress concentration.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Tayyeb Ali, Lin Wang, Xingwang Cheng, Huanwu Cheng, Ying Yang, Anjin Liu, Xuefeng Xu, Zhe Zhou, Zixuan Ning, Ziqi Xu, Xinhua Min
Summary: The study investigates the deformation mechanisms and phase transformations of Ti-5553 alloy under quasi-static and dynamic compression loading. It is found that dislocation slip and twinning are the dominating deformation modes, with grain boundary sliding and spalling more pronounced in quasi-static compression. Stress-induced phase transformations, such as beta to alpha'' and beta to omega, were observed in grains saturated with dislocation slips.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Jishi Zhang, Haijun Liu, Jie Zheng, Jinsheng Ji, Yusha Shi, Leichen Jia, Zhaoming Yan, Beibei Dong, Yong Xue
Summary: The study found that the strain rate affects the fraction and diameter of dynamically recrystallized grains, and different mechanisms under different temperatures lead to different microstructural evolutions.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Materials Science, Multidisciplinary
Jingjing Zhang, Youping Yi, Hailin He, Shiquan Huang, Xianchang Mao, Wanfu Guo, Wen You, Yonglin Guo, Fei Dong, Jiaguo Tang
Summary: Dynamic recrystallization behavior of 2195 aluminum alloy was studied through hot compression experiments, revealing both discontinuous and continuous dynamic recrystallization occurring in the alloy within the temperature range of 300-520 degrees Celsius and strain rates of 0.01-10 s(-1). The dominant DRX mechanism transitioned from DDRX to CDRX when the strain exceeded 1.2, with the number of CDRX grains increasing at higher temperatures or lower strain rates.
MATERIALS CHARACTERIZATION
(2021)
Article
Metallurgy & Metallurgical Engineering
Wenming Xiong, Renbo Song, Ping Yu, Zhijun Liu, Shuai Qin, Yingchao Zhang, Shuyi Quan, Weifeng Huo, Zhiyang Zhao, Shengrui Su, Chen Wei
Summary: The hot deformation behavior of V-Ti microalloyed steel was tested using Gleeble1500, showing characteristics of work hardening and high-temperature deformation softening in the flow stress curve. The combination of a 3D model of dynamic recrystallization and a constitutive equation allows for a comprehensive study of hot deformation behavior under different conditions, providing information on structure evolution as well.
STEEL RESEARCH INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Mariana Poliserpi, Pere Barriobero-Vila, Guillermo Requena, Laura Noel Garcia, Alfredo Tolley, Cecilia Poletti, Tomas Vojtek, Adam Weiser, Norbert Schell, Andreas Stark, Roberto Boeri, Silvana Sommadossi
Summary: This study investigates the microstructure and phase transformation process of IN718/Al/IN718 couples bonded by the Transient Liquid Phase Bonding (TLPB) process at different temperatures, revealing the evolution of the AlNi layer over time and the formation of two distinct layers with varying compositions.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Mariana Poliserpi, Ricardo Buzolin, Roberto Boeri, Cecilia Poletti, Silvana Sommadossi
Summary: This study investigates the development of microstructure in the interconnection zone of an IN718/Al/IN718 couple obtained by the Transient Liquid Phase Bonding (TLPB) process. The results show that the interconnection zone is a multilayered region consisting mainly of sigma, Laves, alpha-Cr phases, and AlNi intermetallic. The AlNi phase is split into two layers with different compositions, and at longer bonding times, it is enriched in Ni and presents nano-precipitates dispersed homogeneously.
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Florian Pixner, Ricardo Buzolin, Anto Zelic, Florian Riedlsperger, Marta Orlowska, Fernando Warchomicka, Mathieu Decherf, Michael Lasnik, Norbert Enzinger
Summary: The study demonstrates the application and tailoring of chromium martensitic hot work steels for wire arc additive manufacturing using metal cored wires. By optimizing the process parameters, additive manufacturing structures were fabricated from chromium martensitic hot-work tool steel alloys, and their microstructure and mechanical properties were characterized.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Alen S. Joseph, Pulkit Gupta, Nilesh Kumar, Maria C. Poletti, Surya D. Yadav
Summary: Modelling the flow behaviour helps to understand the deformation mechanisms in thermo-mechanical processing. Using a physical model based on dislocation density, the flow stress response of 64.7Ni-31.96Cu alloy with different grain sizes was studied under varying temperatures and strain rates. The model incorporates various factors and addresses recovery during plastic deformation. It predicts the effect of grain size and the amount of twins on flow stress.
PHILOSOPHICAL MAGAZINE
(2022)
Article
Chemistry, Physical
Joao Sartori Moreno, Fabio Faria Conde, Celso Alves Correa, Luiz Henrique Barbosa, Erenilton Pereira da Silva, Julian Avila, Ricardo Henrique Buzolin, Haroldo Cavalcanti Pinto
Summary: This study systematically investigates the correlation between pulsed fluxed core arc welding parameters and the performance of the martensitic clad. The results highlight the importance of selecting the appropriate heat input to achieve the desired performance, even when using a pulsed FCAW procedure. Higher heat input appears to be more advantageous in terms of bead morphology, microstructure formation, residual stress, and hardness.
Article
Materials Science, Multidisciplinary
Josef Domitner, Zahra Silvayeh, Ricardo Henrique Buzolin, Sabine Krisam, Klaus Achterhold, Erwin Povoden-Karadeniz, Christof Sommitsch, Peter Mayr
Summary: This study provides detailed experimental characterization of a laser-clad metal matrix composite (MMC) consisting of hard tungsten carbide particles embedded in a comparatively soft nickel-based matrix. The relationship between the microstructure of the as-deposited reinforcing particles and their hardness is investigated. The dissolution of carbides caused by the high process temperature of laser metal deposition (LMD) is observed, leading to the formation of secondary phases at the matrix/particle interfaces and a gradual decrease in local hardness.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Florian Pixner, Ricardo Buzolin, Fernando Warchomicka, Andreas Pilz, Norbert Enzinger
Summary: In this study, the feasibility of wire-based additive manufacturing of commercially pure tungsten using electron beam technique was demonstrated, achieving high density and hardness values. Different AM structures showed different characteristics in terms of appearance and density, with grains coarsening from bottom to top.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2022)
Article
Chemistry, Physical
Evelyn Sobotka, Johannes Kreyca, Maria Cecilia Poletti, Erwin Povoden-Karadeniz
Summary: In this study, a combination of materials modeling and experimental results was used to investigate the evolution of dislocation density in microalloyed steels. It was found that plastic stresses at high temperatures were independent of the precipitation state, and a single set of empirical equations was sufficient to model all investigated microalloyed steels.
Article
Crystallography
Rene Wang, Dinesh Ram, Bernhard Stauder, Ricardo Fernandez Gutierrez, Elisabetta Gariboldi, Maria Cecilia Poletti
Summary: This study systematically measures the relaxation of stresses in Al cast cylinder heads and phenomenologically models the process. It found that the relaxation process is faster at 180°C and 200°C, and slower at 230°C.
Article
Materials Science, Multidisciplinary
Hugo Mora-Sanchez, Florian Pixner, Ricardo Buzolin, Marta Mohedano, Raul Arrabal, Fernando Warchomicka, Endzhe Matykina
Summary: This study investigates, for the first time, the combination of electron beam surface structuring and plasma electrolytic oxidation, aiming to provide a multiscale topography and bioactive surface for Ti6Al4V alloy in biomedical applications. The results show that the electrolytic oxidation process, morphology, and composition of coatings were almost identical regardless of the surface topography. However, the growth rate of coatings was related to specific topographical features. Nevertheless, all the coatings exhibited excellent corrosion resistance.
Article
Materials Science, Multidisciplinary
Ricardo Henrique Buzolin, Tim Richter, Florian Pixner, Michael Rhode, Dirk Schroepfer, Norbert Enzinger
Summary: This study investigates the feasibility of electron beam welding in producing bead-on-plate welds of CrCoNi and CrMnFeCoNi medium and high entropy alloys. The alloys are welded in two different states, namely, as-cold-rolled and annealed conditions, with two different parameters. The FCC microstructure of the welds is examined, and the impact on the microstructure is discussed. The heat-affected zone is negligible in the annealed condition due to the absence of recrystallization and insufficient exposure time to high temperature for grain coarsening.
MATERIALS & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Elisabeth Hengge, Jakob Ihrenberger, Eva-Maria Steyskal, Ricardo Buzolin, Martin Luckabauer, Christof Sommitsch, Roland Wuerschum
Summary: The synthesis of bulk nanoporous copper from a copper-manganese alloy by electrochemical dealloying and free corrosion, as well as the electrochemical behavior and oxide formation of the dealloyed structures, have been investigated. The nanoporous copper exhibited suppressed reordering processes and the formation of a hybrid composite of copper and manganese oxide on its surface. This unique heterogeneous structure shows potential for applications in energy storage and catalysis.
NANOSCALE ADVANCES
(2023)
Article
Nanoscience & Nanotechnology
Ricardo Henrique Buzolin, Markus Masswohl, Franz Miller Branco Ferraz, Konrad Chrzan, Tomasz Dudziak, Maria Cecilia Poletti
Summary: The microstructure of hypo-eutectic high entropy alloys was modified through thermomechanical treatments at 1100°C. Electron backscattered diffraction confirmed two crystal structures: BCC and FCC. Deformation tests at different strain rates revealed that the size and fraction of BCC strongly influenced the deformation of the FCC matrix. The formation of fine BCC particles within the FCC matrix at high temperatures resulted in the pinning of high-angle grain boundaries.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Franz Miller Branco Ferraz, Lukasz Sztangret, Fernando Carazo, Ricardo Henrique Buzolin, Peng Wang, Danuta Szeliga, Pedro dos Santos Effertz, Piotr Maciol, Alfred Krumphals, Maria Cecilia Poletti
Summary: During thermomechanical processing of titanium alloys, restoration phenomena occur in the 13-phase, which is described by a mean-field physical model. Metamodels using Artificial Neural Network and Decision Tree Regression are developed to reduce computational time. These metamodels accurately predict the overall behavior of outputs and demonstrate robustness in heterogeneous deformation.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Ricardo Henrique Buzolin, Markus Masswohl, Franz Miller Branco Ferraz, Konrad Chrzan, Tomasz Dudziak, Maria Cecilia Poletti
Summary: Thermomechanical treatments were conducted on a dual phase hypoeutectic high entropy alloy. Different methods, including hot compression and isothermal soaking, were used to modify the microstructure of the as-cast material. The results showed that strain rate jumps and multi-stage compression had significant effects on the material's stress relaxation and softening. The formation of sigma 3 and the rotation of the eutectic BCC phase and the precipitates played important roles in the microstructural evolution.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)