Article
Chemistry, Multidisciplinary
Tamar L. Greaves, Durga Dharmadana, Dilek Yalcin, Jonathan Clarke-Hannaford, Andrew J. Christofferson, Billy J. Murdoch, Qi Han, Stuart J. Brown, Cameron C. Weber, Michelle J. S. Spencer, Chris F. McConville, Calum J. Drummond, Lathe A. Jones
Summary: This study investigated the corrosive properties of protic ionic liquids on zinc and copper. It was found that the presence of carboxylate anions or alkanolammonium cations led to a cathodic shift in the corrosion potential, with a noticeable decrease in corrosion current for copper and an increase for zinc. The interactions between ionic liquids and metal surface were further explored, revealing that ethanolammonium cation had a stronger binding to the copper surface compared to ethylammonium cation, and nitrate anion was more tightly bound than formate anion.
Article
Chemistry, Physical
Zbysek Novy, Pavel Salvetr, Jakub Kotous, Petr Motycka, Aleksandr Gokhman, Crtomir Donik, Jan Dzugan
Summary: Strain assisted tempering technology can significantly improve the strength of spring steel, while also enhancing notch toughness, but reducing elongation and reduction of area. Acceptable values for these parameters can be achieved through process optimization.
Article
Materials Science, Multidisciplinary
Pavel Podany, Tomas Gregor, Tomas Studecky, Crtomir Donik
Summary: The paper describes the development of austenitic steel with the TWIP effect, which is alloyed with chromium to increase corrosion resistance. The steel was cast, hot and cold rolled, and subjected to appropriate recrystallization annealing to obtain the optimal austenitic grain size. X-ray diffraction confirmed the presence of fully austenitic structure. The steel achieved a TS of more than 950 MPa with an elongation of 40% after recrystallization annealing. The addition of chromium increased the corrosion resistance of the steel.
Article
Chemistry, Physical
David Necas, Jiri Kubasek, Jan Pinc, Ivo Marek, Crtomir Donik, Irena Paulin, Dalibor Vojtech
Summary: In this study, a zinc-based nanograin material was prepared by combining mechanical alloying and spark plasma sintering techniques. The resulting material exhibited fine microstructure, high hardness, and compressive strength, making it a promising candidate for bioabsorbable medical devices.
Article
Chemistry, Physical
Darja Steiner Petrovic, Crtomir Donik, Irena Paulin, Matjaz Godec, Maja Voncina, Martin Petrun
Summary: Lab-scale investigations on the processing of small powder volumes are important for understanding the thermal behavior of high-alloy Fe-Si powder for AM. The study found that the re-melting of the powder led to significant silicon loss and the formation of needle-shaped eutectics. The presence of high-temperature silica eutectics is a weakness for the efficiency of magnetization processes in the Fe-Si alloy system.
Article
Chemistry, Physical
Pavel Salvetr, Andrea Skolakova, Jakub Kotous, Jan Drahokoupil, Daniel Melzer, Zdenek Jansa, Crtomir Donik, Aleksandr Gokhman, Zbysek Novy
Summary: The present study aimed to investigate the properties of medium-carbon steel during tempering treatment and to enhance the strength of medium-carbon spring steels using strain-assisted tempering (SAT). The effects of double-step tempering and double-step tempering with rotary swaging (SAT) on mechanical properties and microstructure were examined. The results showed that SAT treatment significantly increased the yield strength of the medium-carbon steel samples, while reducing the plastic properties such as elongation and reduction in area compared to the double-step tempering treatment. Grain boundary strengthening and lower dislocation strengthening contribution were observed in the SAT samples.
Article
Chemistry, Physical
Jiri Hajek, Zbysek Novy, Ludmila Kucerova, Hana Jirkova, Crtomir Donik, Zdenek Jansa
Summary: The paper discusses the heat treatment possibilities for low-density structural steels used in springs. Different alloy compositions were prepared, including ones with carbon and aluminum. Various tests and analyses were conducted to determine the transformation temperatures, density values, and mechanical properties of the alloys. The results showed that appropriate heat treatment can achieve high tensile strength and hardness for these steels.
Article
Materials Science, Multidisciplinary
Josef Odehnal, Tomas Studecky, Petra Cejkova, Ivana Polakova, Martin Rund, Vaclav Brunat, Petr Martinek, Pavel Francisko, Crtomir Donik
Summary: The aim of this work is to evaluate the cold bending capacity of high-borated austenitic stainless steel sheets. Borated stainless steels, known for their excellent neutron-absorbing capability, are widely used in vertical storage baskets for spent nuclear fuel. Welded seams, which are difficult to make and prone to corrosion, could be minimized by using bent steel semi-products. However, the limited workability of high-borated stainless steels due to their boron content poses a challenge for cold bending. This study focuses on the bending aspects of borated steel sheets with hexagonal cell geometry and provides practical recommendations for rack design.
Article
Materials Science, Multidisciplinary
Jaromir Dlouhy, Crtomir Donik
Summary: Two experimental 0.2C steels with and without 1 wt% Cu were subjected to controlled rolling and subsequent quenching to form a dual ferritic-martensitic microstructure. The severe cooling of the surface layer during the rolling process resulted in a heterogenous microstructure with significantly finer ferritic grains in the surface layer compared to the core. Mechanical properties of the core were unaffected by Cu content, whereas the surface layer exhibited Cu-related strengthening due to Cu precipitation. The mode of ferrite growth from austenite plays a crucial role in the rapid precipitation of Cu in ferrite grains during or shortly after their formation.
Article
Materials Science, Multidisciplinary
Jakob Kraner, Peter Cvahte, Primoz Sustaric, Tomaz Sustar, Crtomir Donik, Irena Paulin, Shae K. Kim, Kyung Il Kim
Summary: Hot rolling is a crucial element in the process chain of aluminum-rolled products, as it affects material quality and productivity. Modifications in hot rolling are necessary to meet higher demands, and considerations must be given to changes in microstructure, crystallographic texture, mechanical properties, and formability. By reducing the thickness of the hot-rolled band, fewer cold rolling passes are required, allowing for hot rolling at lower temperatures. Microstructural and texture characterizations of the hot-rolled bands revealed differences in grain distribution and texture components between the 3.25 mm and 6 mm bands. The mechanical testing results showed significant differences in elongation values and earing, with the 3.25 mm hot-rolled band having higher earing results.
Article
Engineering, Biomedical
Diana C. Martinez, Anna Dobkowska, Romy Marek, Hanna Cwieka, Jakub Jaroszewicz, Tomasz P. Plocinski, Crtomir Donik, Heike Helmholz, Berengere Luthringer-Feyerabend, Berit Zeller-Plumhoff, Regine Willumeit-Roemer, Wojciech Swieszkowski
Summary: This study investigated the degradation of an Mg-0.45Zn-0.45Ca (ZX00) screw in vitro and in vivo. The results showed that the ZX00 alloy promoted bone healing and the formation of new bone. Despite the correlation with the production procedure, the ZX00 alloy was still suitable for temporary bone implants.
BIOACTIVE MATERIALS
(2023)
Article
Engineering, Manufacturing
Pavel Salvetr, Jakub Kotous, Crtomir Donik, Aleksandr Gokhman, Zbysek Novy
Summary: This study investigates the 54SiCr6 high-strength low-alloyed steel with medium carbon content and explores several methods to enhance its mechanical properties, including the influence of ASR on microstructure, thermomechanical treatment, and strain assisted tempering.
MANUFACTURING TECHNOLOGY
(2023)
Article
Chemistry, Physical
Mehmood Irfan, Karma Zuraiqi, Chung Kim Nguyen, Tu C. C. Le, Fahad Jabbar, Mariam Ameen, Caiden J. J. Parker, Ken Chiang, Lathe A. A. Jones, Aaron Elbourne, Christopher F. F. McConville, Dan Yang, Torben Daeneke
Summary: The emergence of liquid metal catalysts improves the efficiency of electrocatalytic processes by eliminating coking issues faced by conventional solid catalysts. Alloying these catalysts with trace amounts of redox-active metal additives further enhances their catalytic activity. This study presents a vanadium-liquid metal alloy with superior activity for electrochemical reduction of CO2 into solid carbon. The reaction mechanism has been thoroughly investigated and discussed. Additionally, machine learning-trained artificial neural networks have shown potential in predicting the performance of liquid metal alloys with different compositions.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Mahendran Manivannan, Venkatachalam Rajagopal, Lalithambigai Krishnamoorthy, Selvam Dhanasurya, Vembu Suryanarayanan, Murugavel Kathiresan, Thasan Raju, Lathe A. Jones
Summary: Metal-organic frameworks (MOFs) have emerged as promising electrocatalysts due to their large specific surface area, high porosity, changeable pore size, and ordered pore arrangement. In this study, trimetallic MOFs (Co-Ni-Al-MOFs) and bimetallic MOFs (Co-Ni-MOFs, Co-Al-MOFs, and Ni-Al-MOFs) were synthesized and characterized for their surface morphology, functional group and elemental analysis. Co-Ni-Al-MOFs exhibited excellent catalytic activity for thiophene electrooxidation, water splitting, and chemical reduction of 4-nitrophenol (4-NP), attributed to their larger surface area and higher pore volume compared to other bimetallic MOFs. The catalytic activity of Co-Ni-Al-MOFs was further evaluated for the reduction of 4-NP to 4-aminophenol (4-AP), showing exceptional activity with a minimum reduction time of 8 min.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Physical
Poonam Yadav, Golu Parte, Wahid Malik, Ylias M. Sabri, Lathe A. Jones, Manjusha Shelke
Summary: The development of high-performance, low-cost electrodes using sustainable materials for Li-ion batteries is crucial for meeting the increasing demand in electronics and electric vehicles. This study introduces a tin ferrite conversion alloying material (CAM) and its composite with a waste-derived carbon to enhance conductivity, diffusion kinetics, stability, and reversibility.
SUSTAINABLE ENERGY & FUELS
(2022)
