Abstract
The effect of TiO₂ additive concentration and sintering temperatures on the densification of alumina (Al₂O₃ ) ceramics were investigated. Densified alumina specimens were prepared by uniaxial pressing at a pressure of 60 MPa followed by isothermal heating at either 1400, 1500, or 1600 o C for 2 h. The relative..... More

Abstract
Cast A356(Al-Si-Mg) alloys are widely used in automotive and general applications because of their mechanical properties and castability. Al-Si-Mg-(Cu) alloys typically lose their strength above 170 o C due to coarsening of precipitates, which limits their application to components. To maintain their strength at elevated temperature, Al-Si-Mg-(Cu) alloys are modified..... More

Abstract
The creep properties of Alloy 690, used as a steam generator tube material in nuclear power plants, were evaluated at 650°C, 750°C, and 850°C. The parameters of creep life prediction models were derived using the Larson-Miller (LM), Manson-Haferd (MH), and Orr-Sherby-Dorn (OSD) models, to use as mechanical properties under a..... More

Abstract
In this study, the relationship between solidification cracking and epitaxial growth behavior with the high-speed laser surface melting of a directionally solidified 247LC superalloys was fundamentally and metallurgically investigated, to develop a successful welding procedure for the next generation of gas turbine blades. Under typical laser surface melting conditions (scan..... More

Abstract
Green hydrogen has attracted significant attention as one of the future energy sources because no greenhouse gases are emitted during production and its energy density is much higher than fossil fuels. Precious metals such as platinum (Pt) and iridium (Ir)-based catalysts are commonly used for water splitting catalysts. However, because..... More

Abstract
We demonstrated a bonding technology using polyethyleneimine (PEI) as a bonding layer between printed Ag electrodes and an emission material layer (EML) to fabricate all-solution-processed Organic LightEmitting Diodes (OLEDs). We manufactured Ag electrodes on a glass substrate by the screen printing method, which was bonded to another substrate with ITO..... More

Abstract
Carbon-based thin film tool coatings, such as diamond-like carbon (DLC), have excellent lowfriction and anti-sticking properties. These thin films are widely used for the cutting and machining of increasingly widely-used lightweight non-metallic and non-ferrous metal materials, as a part of countermeasures against global warming. However, non-metallic and non-ferrous metal materials..... More

Abstract
There is substantial concern about the phase change to artificial ferrite or martensite in commercial austenitic stainless steels during intense focused-ion-beam milling. In this work, severe Ga ion milling to prepare microscale samples was found to produce thin transformed layers on the surface of austenitic stainless steel. The surface BCC..... More

Abstract
The efficiency of gas turbines depends on the gas turbine working temperature. Single crystal blades are being applied more often than equiaxed blades in gas turbine engines, to increase the turbine inlet temperature, resulting in enhanced turbine engine efficiency. Single crystal blades endure creep conditions at high temperature better than..... More

Abstract
In this study, the liquation cracking temperature range (LCTR) of over-aged 247LC superalloy repair welds was quantitatively evaluated using spot-Varestraint testing, especially for application in the repair weld heat-affected zone (HAZ). The metallurgical mechanism of the evaluated liquation cracking susceptibility and variation of the LCTRs of the over-aged 247LC superalloys..... More

Abstract
Macrostructural features in continuously-cast stainless steel slabs such as the distribution of equiaxed and columnar grains, and microporosity, are crucial to the post-processes, and the mechanical properties of the final steel products. Among the methods for controlling grain structure during the continuous casting process, the application of electromagnetic stirring (EMS)..... More

Abstract
Stainless steel-based composites (SMCs) mixed with 316L stainless steel powder and Fe-Cr-B based M alloys powder ed M) powder were manufactured using the powder injection molding (PIM) process, and their microstructure and mechanical properties were investigated. To examine the effect of M content on the properties of SMCs, the M..... More

Abstract
The combination of severe plastic deformation, deformational heat, and frictional heat generated during the high-pressure torsion process has a great effect on microstructural evolutions, including grain refinement, dynamic recrystallization and recovery. In particular, the low melting temperature metallic alloys (e.g., aluminum and magnesium) also induce nano-precipitations in the matrix during..... More

Abstract
In recent decades, many research efforts have been devoted to developing high-performance stretchable strain sensors due to their potential for application in various emerging wearable sensor systems. This work presents a facile yet highly efficient way of modulating the sensing performance of a thin metal film/conductive composite hybrid piezoresistor-based stretchable..... More

Abstract
A gas turbine (GT) blade is a key hot-pass component for advanced GT engines, and should have stable properties under extreme conditions of 1,350°C and 3,600rpm, etc. The GT blade, after operating with nearly 800 equivalent start-stops (ES) or 24,000 equivalent operation hours (EOH), should be replaced due to degradation..... More

Abstract
The strain aging and hydrogen embrittlement behavior of two bake hardening (BH) steels with different microstructures were investigated in this study. The single-phase BH steel was composed of fully ferrite, while the dual-phase BH steel consisted of ferrite and 3 % martensite. The BH index and aging index (AI) of..... More

Abstract
The influence of trace amounts of sulfur (S) on the microstructural evolution, tensile and creep properties in directionally solidified (DS) Ni-based superalloy GTD-111 were systematically investigated. Doping of S in the range of < 1 to 154 ppm resulted in the formation of a Ti₂SC-type carbosulfide phase near the coarse..... More

Abstract
Metallurgical remains such as crucible, mould, slag and tuyere are generated in the production of bronze. The analysis of slag in particular can be used to identify the raw materials, processes and environments (temperature and condition) employed in the bronze fabrication . The Gwanbuk-ri site in Buyeo is known as..... More

Abstract
The gas tungsten arc (GTA) weldability of high-Mn (HMn) steel and austenitic stainless steel (STS) 316L using dissimilar metal welds (DMWs) was investigated, to fabricate a fuel tank for an LNG-fueled ship. Three types of welding fillers, HMn steel, STS 309LMo and Inconel 625, were applied to the DMWs. The..... More

Abstract
This study investigated the microstructure and mechanical properties of Mg-1Gd-1Y-1Zn (at.%) alloys containing designed amounts of Ce or La. The Mg₅(Gd,Zn) phase formed in the as-cast Mg-Gd-Y-Zn-Ce/La alloys and disappeared after a homogenization treatment at 500°C for 24 h. The addition of Ce and La resulted in the formation of..... More

Abstract
Given the social demand for self-powering wearable electronics, it is necessary to develop composite materials that exhibit both good flexibility and excellent piezoelectric performances. Intensive research on synthesis methods and devising characterization techniques for piezoelectric nanomaterials in various forms has been conducted. In particular, characterization techniques for piezoelectric nanomaterials require..... More

Abstract
The ΔEVPSC numerical code based on the elasto-visco-plastic HEM (Homogeneous Effective Medium) provides a multiscale constitutive modeling framework that is suitable for describing a wide range of mechanical behaviors of polycrystalline metals. In this study, an AA6061-T6 aluminum sample was chosen to validate the predictive capability of the ΔEVPSC stand-alone..... More

Abstract
High quality Hg₂Br₂ crystal grown via the physical vapor transport (PVT) process is essential for the fabrication of the acousto-optic tunable filters (AOTFs) module. The full process flow, including powder purification and crystal growth, should be systematically established, but there have been few reports about the fully established process flow..... More

Abstract
Hydrogen is considered an attractive energy resource because it is eco-friendly in contrast with fossil fuels. Hydrogen storage remains as essential technology for increasing the use of the hydrogen in applications such as hydrogen vehicles and fuel cells. Hydrogen storage requires retaining a high density of hydrogen molecules at ambient..... More

Abstract
The elevated temperature strength of multicomponent Al-Si alloys is greatly affected by the volume fraction and the interconnectivity of hard phases formed upon solidification. In the present investigation, such influences were examined for two Al-Si-Cu-Ni alloys with different total volume fractions of hard phases. To control the microstructural features related..... More

Abstract
Nodular graphite cast iron is used in the railway and automobile industries because of its excellent workability, abrasion resistance, mechanical strength, and hardenability. To use nodular graphite cast iron in harsh environments, it is essential to examine their friction–wear properties in conjunction with the surface hardness of the materials. Therefore,..... More

Abstract
Due to its high theoretical capacity in the conversion reaction, Co₃O₄, a transition metal oxide, has been attracting attention as an anode material for lithium-ion batteries. Comparing conventional slurry method with the electrophoretic deposition (EPD) method without additives (conductive agents and binders), we investigated the effect of the Co₃O₄/additive interface..... More

Abstract
The hot deformation behavior of medium-carbon Cr-Mo alloy, which has been developed for high strength cold-heading quality wire rod, was investigated to evaluate its hot workability. A flow curve was derived using the hot torsion test, under conditions with temperatures of 1173-1273 K and strain rates of 0.1-1.0 s^-1. At..... More

Abstract
Recently, lightweight vehicle bodies are in increasing demand to satisfy exhaust gas and environmental regulations around the world. In particular, aluminum alloys are widely used to manufacture lightweight parts, because of their excellent properties including corrosion resistance and mechanical properties. After the forming process, the welding process is important for..... More

Abstract
The effect of Cu content on the microstructure and mechanical properties of Al-8.0Zn-2.5Mg-xCu (x: 0, 1, 2, 3) aluminum alloys manufactured by the twin-roll casting process was investigated. The Al-8.0Zn-2.5Mg-xCu alloy showed an increase in surface defects with increasing Cu content. This is because the amount of residual liquid in..... More