Abstract
The Charpy impact test is used to identify the transition between ductility and brittleness. The percentages of ductile and brittle fractures in steel can be evaluated based on each fracture area, which is presently determined by an analyzer with the naked eye. This method may lead to subjective judgement, and..... More

Abstract
Using thermoelectric refrigerators can address climate change because they do not utilize harmful greenhouse gases as refrigerants. To compete with current vapor compression cycle refrigerators, the thermoelectric performance of materials needs to be improved. However, improving thermoelectric performance is challenging because of the trade-off relationship between the Seebeck coefficient and..... More

Abstract
Hydrogen flowing into a weld causes hydrogen embrittlement (HE), so to prevent cold cracks in the weld, HE must be suppressed. In this study, single-pass fillet weldments were fabricated using two different welding fillers with the same strength level as the American Welding Society standard. The specimen F-HNi, which had..... More

Abstract
In ironmaking, the optimal size of the iron ore charged into a blast furnace is generally 10-30 mm. Oversized ores, which have a smaller reaction surface area, are crushed, while undersized ores, which decrease permeability, undergo a sizing process before being charged into the blast furnace. Recently, however, iron ore..... More

Abstract
Nickel hexacyanoferrate (NiHCF) has a three-dimensional open framework structure, excellent long-cycling stability and rate performance as a cathode for aqueous sodium-ion batteries. However, the specific capacity of NiHCF is lower than that of present cathodes for aqueous batteries. A sodium-ion electrolyte was explored to achieve optimum capacity with NiHCF. Powder-type..... More

Abstract
In this study, the effects of electrode surface design on the resistance spot weldability and degradation of the electrode following resistance spot welding (RSW) of aluminum 6014-T4 alloy were investigated. A new patterning method that can be produced through repetitive pressurization was applied to the electrode, producing a lattice-like pattern..... More

Abstract
In this study, oxide (Y₂O₃)-embedded Ni particles were fabricated via a new process. The process involves the mechanical hydrogenation of Ni–Y alloy into Ni–YH₂ and the selective oxidation of Ni–YH₂ to Ni–Y₂O₃. The alloy powders were prepared for sintering by the mechanical alloying of a mixed powder. The powder was..... More

Abstract
The effects of the cooling rate, after solution heat treatment, on the microstructures and mechanical properties of Fe-22Mn-8Al-0.8C-0.02Nb (low carbon) and Fe-20Mn-8Al-1.1C-0.1Nb (high carbon) light-weight steels were systematically investigated. The cooling process was controlled to achieve six different cooling rates, ranging from -0.016 to -465.1 ^oC/s. Under the slowest cooling..... More

Abstract
To automatically reconstruct the prior austenite grains from as-quenched martensitic structure, we applied a deep learning algorithm to recognize the prior austenite grains boundaries hidden in the martensitic matrix. The FC-DenseNet architecture based on FCN (fully convolutional networks) was used to train the martensite and ground truth label of the..... More

Abstract
This study investigated the effects of laser power on the microstructure and mechanical properties of functionally gradient materials (FGM) produced by direct energy deposition. The FGM consisted of five different layers, which were a mixture of austenitic stainless steel (Type 316L) and ferritic steel (HSLA). During the direct energy deposition,..... More

Abstract
ZrO₂ is a promising candidate for knee and hip joint replacements due to its excellent combination of low density, corrosion resistance and biocompatibility. Nevertheless, a low fracture toughness of pure ZrO₂ at room temperature limits its wider application in the industry. One of the most obvious ways to solve the..... More

Abstract
Recent large-scale fires in buildings and logistic warehouses have become a major social issue, involving both property loss and multiple casualties. To make color coated steel sheets non-combustible and/or have anti-fire properties, various ways of optimizing manufacturing parameters have been investigated for outer, inner, roof and ceiling panels. In the..... More

Abstract
In this study, high-strength pure Cu bulk material was manufactured using a cold spray additive manufacturing process, and its microstructure, tensile and compressive deformation behaviors were investigated and compared. The cold spray additive manufactured Cu bulk material showed a heterogeneous grain structure consisting of fine-grains and coarse-grains, and only α..... More

Abstract
The flow functions for plastic deformation have been developed to describe the plastic behavior of sheet metals. In order to explain the plastic behavior of material in metal forming processes via finite element analyses, two basic input functions should be applied. One is the yield function that determines the yielding..... More

Abstract
We introduce the Korea Institute of Science and Technology-Novel Materials Discovery (KISTNOMAD) platform, a materials data repository. We describe its functionality and novel features from an academic viewpoint. It is a data repository designed for computational material science, especially focusing on managing and sharing the results of molecular dynamics simulation..... More

Abstract
In this study, the critical role of substrate bias during the sputter deposition of Al thin films is discussed. Two sets of Al thin films having a nominal thickness of 300 nm were deposited at sputtering pressures of 4.1 and 1.5 mTorr, respectively, with an applied negative substrate bias in..... More

Abstract
Al-Mg-Si alloy was rolled asymmetrically at several temperatures to apply shear deformation, and the effects of the initial precipitate on shear deformation, texture evolution, formability, and plastic anisotropy were studied. Texture was analyzed using a EBSD, and the formability and plastic anisotropy of the specimen were evaluated using the value..... More

Abstract
The thermal storage tank in a district heating system is a component that stores excess heat during normal operation and releases the stored heat to increase the efficiency of the system, when the heat source is stopped or additional demands occur. Recently, an obsolete thermal storage tank was dismantled for..... More

Abstract
This study aimed to investigate the wear performance of laser direct energy deposited Fe-8Cr3V-2Mo-2W alloy under various wear environments, in terms of different heat treatment conditions. Ball on disk tribology tests were performed using high-carbon steel and zirconia balls as counter materials. The wear rates of the alloy depended significantly..... More

Abstract
The effects of β phase decomposition on recrystallization and texture variation in Zr-2.5% Nb alloy pressure tube material were investigated. Isothermal annealing was conducted at 350 to 550 ^oC for 240 hours, and isothermal annealing was performed at 500 ^oC for 240 to 3,000 hours. The recrystallization and texture variation..... More

Abstract
Fe-Mn-Si based shape memory alloy is a new functional material that can be used to apply prestress to civil and structural components such as concrete structures. In this study, the effects of alloying elements Ni, C and Ti on the mechanical and shape memory properties of the alloy were investigated..... More

Abstract
The phenomena of hydrogen induced cracking (HIC) in 304 stainless steels was considered in a hydrogen pressure and stress corrosive atmosphere. Microstructures with chloride pits and stress corrosion cracks around the HIC were analyzed by SEM/EDS. Abnormal phase transformations induced by the hydrogen were analyzed using TEM and diffraction. In..... More

Abstract
We fabricated a transparent conducting electrode composed of graphene oxide (GO) and silver (Ag) nanofibers. The graphene oxide was spray-coated on the Ag nanofiber film, which was fabricated by electrospinning process. Ag/poly(vinyl alcohol) ink was fabricated in a polymer matrix solution using the solgel method. The sprayed film was sintered..... More

Abstract
To clearly understand the effect of the eutectic structure in the Zn-Al-Mg alloy coating on the corrosion behaviors in chloride containing aqueous environments, a bulk Zn-MgZn₂ sample was fabricated by diffusion bonding process, and a variety of experiments, such as electrochemical polarization and galvanic corrosion measurements, salt spray tests, and..... More

Abstract
Hydrogen diffusion and sulfide stress cracking of simulated heat-affected zone (HAZ) of A516- 65 grade steel were examined using an electrochemical permeation technique, glycerin volumetric method, and constant loading method. HAZ samples were fabricated using a metal thermal cycle simulator with a welding heat input of 20, 35, and 50..... More

Abstract
Austenitic stainless steel SS304 is vulnerable to Cl atmosphere SCC (stress corrosion crack). In this study, SCC phenomena related to stress and corrosion composition were analyzed to identify the mechanism for SCC initiation and propagation in SS304. The microstructure and mechanical properties resulting from crack propagation were analyzed by OM,..... More

Abstract
Al-Si coated ultra-high strength steels (UHSS) are widely used in automotive applications because of their high strength-to-weight ratio, corrosion protection and good weldability. The hot stamping (also called hot press forming) process is an effective and suitable technique for producing automotive parts from Al-Si coated UHSS. However, critical issues, such..... More

Abstract
This study investigated the influence of laser shock peening without coating (LSPw/oC) on the degradation of copper electrical contacts. A theoretical calculation of the plastic-affected depth (PAD) induced by LSPw/oC was performed, based on the laser-induced plasma pressure along with the Hugoniot elastic limit of our LSPw/oC experimental conditions. The..... More

Abstract
Recently, various worldwide studies have been conducted to improve converter operation by modifying the lance nozzle. In this study, a numerical analysis of the lance nozzle was conducted to improve the dephosphorization efficiency, and to reduce blowing time. The lance nozzle was designed in the form of an abnormal expansion..... More

Abstract
In this study, consolidated WC-Fe compacts as a function of Fe contents were fabricated by a spark plasma sintering method, following the mixed by the ball-milled powder. Fe among the metallic binders was added to WC enhance not only the driving force of sintering process but also suppressing the grain..... More