Article
Materials Science, Ceramics
Jishi Du, Xiaojun Huang, Mengmeng Wang, Huali Zhang
Summary: Sintering in pure O2 enhances the densification of oxide ceramics during the final stage, but the heating rate has a significant effect on the densification process.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
A. Kumar, M. Bernet, L. Deillon, M. Afrasiabi, M. Bambach
Summary: This paper presents a two-stage approach that integrates direct experimental measurements with numerical simulations, providing a more comprehensive and reliable basis for identifying material parameters in spark plasma sintering (SPS) process. The authors develop a finite element-based fully coupled process model and validate it experimentally. By applying their parameter identification procedure to copper and nickel SPS at different heating rates, the authors achieved an average prediction error below 1.5%. This robust numerical-experimental approach can be used for other commonly used materials in SPS.
MECHANICS OF MATERIALS
(2023)
Article
Chemistry, Physical
Anis Aliouat, Guy Antou, Nicolas Pradeilles, Vincent Rat, Alexandre Maitre
Summary: This study aims to investigate the effects of electric/electromagnetic fields generated by pulsed current in Spark Plasma Sintering (SPS) on the sintering mechanisms. The chosen model material was pre-oxidized copper composed of microsized particles. The results showed that increasing the frequency of pulsed current significantly reduces the critical time for electrical transition. Additionally, the coupling between pulsed current and mechanical stress promotes specific mechanisms in SPS.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Ceramics
Fengxian Zhu, Xinyu Peng, Jinling Liu, Dianguang Liu, Ke Ren, Yiguang Wang
Summary: The study found that in AC flash sintering, the temperature of the sample is symmetrically distributed along the length of the electric field, unlike the asymmetrical distribution in DC flash sintering. The steady stage temperature depends on current density and increases with current density.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Muhammad Imran, Lea Deillon, Irina Sizova, Bram Neirinck, Markus Bambach
Summary: This study focuses on the possibility of manufacturing multi-material structures using spark plasma sintering (SPS), expanding the application of this process by utilizing the specific properties of different materials. By characterizing the sintering behavior of two different materials, CuCrZr and nickel, at various conditions, and representing the densification data using master sintering curves and surfaces, optimal sintering conditions were determined for processing multi-material structures. CuCrZr-Ni multi-material samples were successfully sintered using these parameters.
MATERIALS & DESIGN
(2022)
Article
Plant Sciences
Hongli Zhou, Qiang Zhao, Ru He, Wei Zhang, Huijun Zhang, Haiying Wang, Xue Ao, Xingdong Yao, Futi Xie
Summary: This study found that nitrogen enrichment during the R1 stage of soybeans can improve the absorption and assimilation capacity of nitrogen, increasing the nitrogen content in soybean plants. High-yield cultivars absorb nitrogen faster, and nitrogen enrichment regulates the assimilation capacity of nitrates and ammonia.
JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION
(2022)
Article
Engineering, Mechanical
Jingdong Hu, Changjun Liu, Fuzhen Xuan, Bo Chen
Summary: A mechanistic-based cavitation model is proposed to predict the number density of cavities considering nucleation, early-stage growth, and sintering. The study reveals that initial compression promotes higher cavity number density compared to initial tension. The cavity number density does not have a monotonic dependence on compressive hold time or stress due to the competing effects of nucleation and sintering. The optimum value of stress variation rate exists for obtaining the highest cavity number density due to sintering effect.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Materials Science, Ceramics
Allison S. Brandvold, Waltraud M. Kriven
Summary: This study investigated the influence of temperature on the viscosity of potassium geopolymer pastes. The results showed that temperatures above 30 degrees C resulted in an exponential increase in viscosity due to the intensified geopolymerization reaction. Higher shear rates delayed the increase in viscosity but did not stop it. Yield stress values increased with higher temperatures. The study also found that viable printing times for temperatures of 50 degrees C or above were as little as 50-60 minutes.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Mechanics
Hussein J. Zekri, A. A. Korobkin, M. J. Cooker
Summary: This study explores the hydrodynamics of a symmetric body entering water, finding that gravity affects the contact region size, hydrodynamic pressure, free surface elevation, and total force on the body, especially in the early stages of impact. While the impact of gravity on water impact characteristics is generally considered small, it should still be accounted for in models.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Filipe Richheimer, David Toth, Bekele Hailegnaw, Mark A. Baker, Robert A. Dorey, Ferry Kienberger, Fernando A. Castro, Martin Kaltenbrunner, Markus C. Scharber, Georg Gramse, Sebastian Wood
Summary: This study investigates the early-stage degradation of organic-inorganic halide perovskite films using electrical scanning probe microscopy and identifies the formation of lead iodide nanograins as a key contributor to the instability of perovskite. The intrinsic instability is found to be related to the polycrystalline morphology and can be accelerated by enhanced ionic mobility under optical excitation. Inhibiting the formation of local charge imbalance is crucial for extending the operational stability of perovskite photovoltaics.
Article
Construction & Building Technology
Rui Sun, Dongmin Wang, Yiren Wang, Zhonghua Fang, Shuangcheng Zhang
Summary: This study investigates the use of desulphurisation ash-steel slag-cement (DASSC) composite cementitious material, which combines sintering flue gas desulphurisation ash (DA) and steel slag (SS) with ordinary Portland cement (OPC). The addition of NaOH, Na2SO4, tri-isopropanolamine (TIPA), and silica fume (SF) improves the hydration reaction and enhances the strength of the material while reducing its porosity.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Chemistry, Physical
Hongren Shen, Jianpeng Zou, Yimin Li, Dongyang Li, Yong Yu, Xiao Wang
Summary: In this study, gas-atomized Fe17Cr11Mn3Mo powders were nitrided to obtain different nitrogen contents, and the effects of nitrogen on the predominant sintering mechanism during the initial stage of high nitrogen nickel-free stainless steel powder were studied. It was found that most of the nitrogen in both powders and sintered bodies was uniformly distributed in the form of solid solution, hindering the diffusion of metal atoms. The results showed that the main obstacle to neck growth was solid solution nitrogen rather than surface nitrides.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Tanna Elyn Rodrigues Fiuza, Marlon Muniz da Silva, Jefferson Bettini, Edson Roberto Leite
Summary: This study conducted in situ experiments using high-resolution transmission electron microscopy (HRTEM) to investigate the sintering process at the nanoscale. The researchers observed a high anisotropic pore elimination and identified the atomic rearrangement and attachment process. The findings contribute to enhancing the kinetic models for the densification process of systems at the nanoscale.
Article
Chemistry, Physical
Maksim S. Boldin, Alexander A. Popov, Evgeni A. Lantsev, Aleksey Nokhrin, Vladimir N. Chuvil'deev
Summary: This article presents the investigation results of the densification behavior mechanism of alumina-based ceramics during spark plasma sintering. The effects of heating rates and additives were studied. The study showed that grain boundary diffusion and particle accommodation control the formation of necks between particles in the initial stage of sintering. Additives only have an effect on the final stage of spark plasma sintering.
Article
Engineering, Environmental
Thien-Phuc Nguyen, Mitsuhiko Koyama, Kiyohiko Nakasaki
Summary: This study aimed to investigate the recovery of organic matter decomposition after the transition from oxygen deficiency to aerobic conditions during composting. The results showed that the organic matter decomposition was reduced by 10% and 19% in runs LN3dA and LN5dA respectively, compared to fully aerobic composting. High-throughput sequencing analysis revealed differences in bacterial communities between the early thermophilic stage with oxygen deficiency and fully aerobic composting. Caldibacillus proliferated in LN3dA and LN5dA, while Bacillus dominated in LA. Enzymatic activity analysis also showed differences between all composting runs, with low activity of alpha-galactosidase during oxygen deficiency.
Article
Chemistry, Multidisciplinary
Kang Dong, Henning Markoetter, Fu Sun, Andre Hilger, Nikolay Kardjilov, John Banhart, Ingo Manke
Article
Materials Science, Multidisciplinary
A. S. Semenov, J. Trapp, M. Noethe, O. Eberhardt, T. Wallmersperger, B. Kieback
JOURNAL OF MATERIALS SCIENCE
(2019)
Article
Chemistry, Physical
Kang Dong, Markus Osenberg, Fu Sun, Henning Markoetter, Charl J. Jafta, Andre Hilger, Tobias Arlt, John Banhart, Ingo Manke
Article
Chemistry, Multidisciplinary
Andrea Fantin, Tobias Scherb, Janka Seeger, Gerhard Schumacher, Uta Gerhards, Mariya E. Ivanova, Wilhelm A. Meulenberg, Roland Dittmeyer, John Banhart
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2019)
Article
Instruments & Instrumentation
A. M. Al-Falahat, N. Kardjilov, T. V. Khanh, H. Markoetter, M. Boin, R. Woracek, F. Salvemini, F. Grazzi, A. Hilger, S. S. Alrwashdeh, J. Banhart, I. Manke
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2019)
Article
Multidisciplinary Sciences
Francisco Garcia-Moreno, Paul Hans Kamm, Tillmann Robert Neu, Felix Buelk, Rajmund Mokso, Christian Matthias Schleputz, Marco Stampanoni, John Banhart
NATURE COMMUNICATIONS
(2019)
Article
Nanoscience & Nanotechnology
Meng Liu, Qianning Guo, Xingpu Zhang, Manuel Wustenhagen, Jakub Cizek, John Banhart
SCRIPTA MATERIALIA
(2020)
Article
Chemistry, Physical
De Ning, Aykut Baki, Tobias Scherb, Jia Song, Andrea Fantin, Xinzhi Liu, Gerhard Schumacher, John Banhart, Henny J. M. Bouwmeester
SOLID STATE IONICS
(2019)
Article
Metallurgy & Metallurgical Engineering
Johannes Trapp, Artem Semenov, Oliver Eberhardt, Michael Noethe, Thomas Wallmersperger, Bernd Kieback
Article
Mathematics, Interdisciplinary Applications
A. S. Semenov, J. Trapp, M. Noethe, O. Eberhardt, B. Kieback, T. Wallmersperger
Summary: The research presents a numerical modeling approach for simulating the initial stage of consolidation during spark plasma sintering, considering thermo-electro-mechanical and diffusion problems and using a non-linear formulation to handle plastic and creep strain accumulation. The numerical model developed for simulating structural evolution of particles during sintering shows excellent agreement with experimental results for densification of a copper powder compact.
COMPUTATIONAL MECHANICS
(2021)
Article
Materials Science, Multidisciplinary
Ningzhen Wang, Mike Andreas Noack, Paul Hans Kamm, John Banhart, Francisco Garcia-Moreno
Summary: Ordering the bubbles of closed-cell aluminum foams can enhance decorative esthetics and create directional mechanical properties, with aluminum foams featuring smaller cell sizes capable of forming short-range ordered structures.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Xingpu Zhang, Meng Liu, Jiangwei Wang, Jixue Li, John Banhart
Summary: The combined effects of Sn addition and pre-ageing on the natural secondary ageing and subsequent artificial ageing of AA6014 alloy were investigated. It was found that pre-ageing can suppress natural secondary ageing and improve the artificial ageing hardening kinetics and response. In the case of Sn-added alloy, the effect of pre-ageing can be further improved by natural ageing before pre-ageing at 100℃.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Materials Science, Characterization & Testing
Ingo Manke, Nikolay Kardjilov, Rainer Schneider, Astrid Haibel, Andrea Denker, Alexander Rack, Andre Hilger, Francisco Garcia-Moreno, John Banhart
Summary: This article provides an overview of the important applications of non-destructive testing methods at Hahn-Meitner-Institut in Berlin.
Article
Metallurgy & Metallurgical Engineering
Johannes Trapp, Artem Semenov, Michael Nothe, Thomas Wallmersperger, Bernd Kieback
Article
Materials Science, Multidisciplinary
Meng Liu, Xingpu Zhang, Benedikt Korner, Mohamed Elsayed, Zeqin Liang, David Leyvraz, John Banhart