Abstract
Abstract: High-entropy alloys (HEAs), which are defined as a single phase crystalline solid solution with the composition of each constituent element in the range of 5-35 at%, have been the subject of intensive study in the last decade. Most of the HEA research is focused on alloy design, microstructural characterization,..... More

Abstract
Age hardening and re-crystallization softening of a type of high entropy alloy, CoCrFeMnNi, was performed to investigate the relationship between microstructure and the property of mechanical hardness. Equiatomic CoCrFeMnNi was produced by casting followed by homogenizing, cold rolling and post heat treatments. TEM analysis revealed that the microstructure of the..... More

Abstract
Brake judder is a kind of low-frequency brake vibration and noise phenomenon generated during braking. Various types of judder have been reported, depending on the particular generation mechanism. However, the correlation between the microstructure of gray iron brake discs and judder has seldom been discussed in the literature. In this..... More

Abstract
In this study the hydrogen embrittlement characteristics of three high-manganese steels were tested using different hydrogen charging methods, and the results were compared with various Mn-containing steels. The results showed that the hydrogen embrittlement susceptibility of the high-manganese steels increased with increasing inherent strength because deformation mechanisms, such as deformation..... More

Abstract
In this study, Al alloy targets were fabricated using the powder metallurgy (pulsed current activated sintering, PCAS) process for metal PVD coating target applications. Powders were prepared from Al, Si and Cu ingots for sintering Al alloy compacts using the gas atomizing process. To fabricate the gas atomized Al alloy..... More

Abstract
Interstitial free (IF) steel disks were subjected to various degrees of revolution during application of the high-pressure torsion (HPT) process, and the resulting distributions of hardness and microstructure during the early torsion stage of high-pressure torsion (HPT) were investigated using experimental and simulation approaches. The results indicated that the deformation..... More

Abstract
A new aluminum welding wire with 0.8 wt% higher in Mg content was developed and compared with commercial welding wire of the 5000 series. The weldability of the Al5083 base material was evaluated using high current metal inert gas (MIG) welding, using the developed Al5183 and commercial Al5183 welding wire...... More

Abstract
The separation of Re(VII) and V(V) by solvent extraction with TBP was investigated by varying the HCl, metal and chloride ion concentrations. Re(VII) was selectively extracted over V(V) from the HCl solution. The highest separation between Re(VII) and V(V) occurred at a concentration of 2.0 M HCl. The extraction reaction..... More

Abstract
In this study, we made large-scale ingots of CoCrFeMnNi high entropy alloy by vacuum induction melting. The as-cast CoCrFeMnNi high entropy alloy contained a high proportion of columnar structures with a few equiaxed grains, and showed single phase fcc solid solutions without macro segregation and low interstitial levels. The tensile..... More

Abstract
Nanocomposite films, which are comprised of metal nanoparticles dispersed in a matrix layer, have attracted great interest due to their unique electrical and optical properties, which are mainly due to the excitation of localized surface plasmons. In this study, we employed an alternating sputtering method to fabricate such nanocomposite films...... More

Abstract
Korea is famous for more than a millennium of continuous fabrication of Cu-Sn objects with near peritectic composition through a process of forging and rapid cooling at approximately 700 °C. We examined four high tin bronze hairpins excavated from two Unified Silla sites in Gyongju and found substantial variability reflecting..... More