Abstract
A Ni-Cr-B-Si-C coating layer was manufactured on a plate of Fe base alloy using a laser cladding process, and the microstructural and mechanical properties of the laser cladded coating layer and a Ni electroplating layer (used as a reference material) were investigated. To identify the microstructural and mechanical properties, scanning..... More

Abstract
In the present study, the correlation of microstructural factors with yield ratio and uniform elongation was investigated in API X80 linepipe steels with different microstructures by varying thermomechanical control process conditions. The grain size and microstructure fraction of the API X80 linepipe steels were quantitatively measured by EBSD analysis and then..... More

Abstract
Microstructure evolution and the creep fracture characteristics of dissimilar welds between Ni-based superalloy Inconel 740H and High Cr ferritic steel Gr.92 were investigated. The dissimilar welds were fabricated by shielded metal arc (SMA) welding process with Ni-based austenitic Inconel 182 superalloy. Postweld heat treatment at 760 ^oC for 4 hours..... More

Abstract
The effects of heat treatment and thermal cycle conditions on the bonding strength and interfacial characteristics of electroplated Cr/electroplated Ni-P coatings were systematically evaluated. With step1 samples, heat treatment was performed at 750 ^oC for 6 hours after successive electroplating of Ni-P and Cr layers. With step2 samples, 1st heat..... More

Abstract
Samples with compositions of 99 w/o MgH₂+1 w/o Zn(BH₄)₂ (designated MgH_2-1Zn(BH₄)₂) and 96 w/o MgH₂+2 w/o Zn(BH₄)₂₊2 w/o Ni (designated MgH_2-2Zn(BH₄)_2-2Ni) were prepared by milling in a planetary ball mill in a hydrogen atmosphere (reaction-involving milling). The hydrogen release properties of MgH_2- 1Zn(BH₄)₂ and MgH_2-2Zn(BH₄)_2-2Ni were compared. A larger quantity..... More

Abstract
In this study, the effects of hot forging and heat treatment (quenching and tempering) of cast Cr alloy steel on the microstructures and mechanical properties were investigated. The hot forging was performed at a compressive ratio 0.5 at 1,250 ^oC. The heat treatment process was quenching (860 ^oC for 2..... More

Abstract
Rhenium coatings were fabricated on a graphite substrate at 1100 and 1250 ^oC and a molybdenum substrate at 1150 and 1250 ^oC by chemical vapor deposition (CVD) using ReCl5 precursor, and the effects of deposition temperatures and substrates on microstructure and crystal orientation were investigated. The rhenium coating on graphite..... More

Abstract
This study manufactured Fe-Cr-Ni-based alloy (HK30) using the metal injection molding (MIM) process and investigated the microstructure and room·high temperature mechanical properties of the material. The effect of hot isostatic pressing (HIP) on properties was also examined. The average grain sizes were 24.1 µm for an MIM specimen and 29.1..... More

Abstract
High entropy alloys (HEAs) are a relatively new class of metallic materials. HEAs lead to high mixing entropy and the formation of a simple solid solution rather than intermediate phases. This might be explained by the fact that the configurational entropy outweighs the enthalpy of formation of intermetallic compounds. Meanwhile,..... More

Abstract
Since strength and ductility have a trade-off relationship in Al alloys, controlling these properties using heat treatments requires careful attention to the dissolution and evolution of the reinforcing phases. In this study, the effects of solution and aging treatments on the microstructure and mechanical properties of Al-5.2Si-3.4Cu-0.28Mg alloy were investigated...... More

Abstract
This study investigated the microstructure and the ambient-elevated temperature compression and elevated temperature creep properties of Fe-14Cr ferritic ODS steel manufactured by mechanical alloying (high energy ball milling) and hot extrusion processes. Initial microstructural observation of the as-extruded material identified elongated grains in the direction of extrusion; however, some recrystallization..... More

Abstract
The effects of cooling after solution heat treatment on the microstructure and mechanical properties of light-weight steels were investigated using Fe^-30Mn^-xAl^-0.9C alloys containing 9.0–12.8 wt% Al. Lab^-scale specimens (thickness: 10 mm) of the alloys were cooled by different cooling rates from -337 to -0.053 ℃/s using water, air, and furnace..... More

Abstract
A polycrystalline diamond compact (PDC) is a two-stage sintered body manufactured by placing diamond powders on a WC-Co hard material and then applying the high pressure high temperature (HPHT) sintering process. This study investigated the microstructure and wear properties of the PDC depending on initial diamond particle size. Three different..... More

Abstract
In this study, the effects of microstructural variations in heavy-section reactor pressure vessel (RPV) steels on tensile and Charpy impact properties were investigated. Two PRV blocks, OPR1000 and APR1400 (ORV, ARV) were taken from the archive materials used in Korea standard nuclear power plants. Test specimens were sampled from five..... 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
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
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
A new Ni based superalloy with high fatigue resistance and fine grain was considered as a material for high-pressure buckets in fossil fuel power plants. Since such buckets are usually exposed to extreme operating conditions, low cycle fatigue tests were conducted to understand the microstructure evolution of the material during..... More

Abstract
The effects of oxygen content on the β to α phase transformation of the Ti-5Al-2.5Fe alloy during continuous cooling were investigated by varying the oxygen content between 0.08 – 0.41 wt%. Dilatometer tests were performed at cooling rates of 0.05 – 100 ℃/s combined with microstructure observation to examine phase..... More

Abstract
To study the effect of Al and Zr contents on the microstructural changes and tensile properties of Ni-Al-Bronze alloy, seven specimens were cast with different Al and Zr contents. The microstructure observation revealed that all specimens were composed of β’ and κ phases in a α matrix. With increasing Al..... More

Abstract
A new Ni based superalloy is considered as bucket material because of high fatigue resistance with fine grain. However a bucket is usually exposed to high temperature for a long time, so creep rupture tests were conducted to understand the microstructure evolution during creep deformation under various stresses at temperatures..... More

Abstract
The influence of ultrasonic melt treatment (UST) combined with a change in cooling rates on the microstructure and elevated temperature mechanical properties of a hypereutectic Al-18Si-4Cu-3Ni piston alloy was investigated. Microstructural observation confirmed that UST effectively refined the sizes of primary Si and intermetallic compounds (e.g. ε-Al₃Ni) while promoting their..... More

Abstract
The resistance of hydrogen induced cracking (HIC) was investigated with different microstructures of API X70MS steel. Ferrite/acicular ferrite (F/AF), deformed ferrite/acicular ferrite, ferrite/bainite (F/B) and single acicular ferrite (AF) were obtained by thermo-mechanical controlled process (TMCP) with changing rolling and cooling conditions. HIC resistance was found to be affected by..... More

Abstract
In this paper, Cu-coated graphite powders for a low thermal expansion coefficient and a high thermal conductivity are fabricated using a chemical reaction process. The Cu particles adhere to the irregular graphite powders and they homogeneously disperse in the graphite matrix. Cu-coated graphite powders are coarser at approximately 3~4 ㎛..... More

Abstract
The effect of ultrasonic melt treatment (UST) on the microstructure and mechanical properties of Al-7Si-0.35Mg (A356) casting alloys was investigated. The particular aim of this study was to analyze the mechanism involved in the strengthening of the A356 alloys when fabricated by UST. The UST had little effect on the..... More

Abstract
The effects of nitrogen content on the HAZ softening of Ti-containing high strength steels manufactured by accelerating cooling were investigated and interpreted in terms of the microstructures in the softening zone. Regardless of their content, all of the steels investigated showed a softened zone 9-10 mm wide. The minimum hardness..... More

Abstract
In this study, the effect of α and β those stabilizers on the microstructure and phase transformation of cast Ti-6wt%Al-4wt%V alloy at various solution treatment temperatures was investigated. The dependence of the transformation behavior of the β phase during the solution treatment and its dependence was determined by the partitioning..... More

Abstract
In order to study the effect of microstructural change on the tensile properties of discontinuous precipitated Al-Zn binary alloy, four different Al-Zn alloys(25, 30, 35, 45 wt% Zn) were aged at 160 ℃ for different aging times(0, 5, 15, 30, 60, 120, 360 min) after being solution treated at 400..... More

Modeling and Simulation

Abstract
Yttrium Aluminum Garnet (YAG) single crystal has received much attention as the high power solid-state laser’s key component in industrial and medical applications. Various growth methods have been proposed, and currently the induction-heating Czochralski (IHCZ) growth method is mainly used to grow YAG single crystal. Due to the intrinsic properties..... More