Abstract
In the present work, MgH2 was doped with Zn(BH4)2, Ni, and/or Ti to improve its hydrogen absorption and release features. Samples were prepared by grinding in a planetary ball mill in a hydrogen atmosphere. To increase the hydrogen absorption and release rates without significantly sacrificing hydrogenstorage capacity the additive percentages..... More

Abstract
This study investigated and compared the tensile and high-cycle fatigue properties of AISI 1045 steel and Cr electroplated AISI 1045 steel. First, tensile and fatigue specimens were machined from AISI 1045 steel (substrate), and two kinds of Cr electroplating layers with different layer thickness were applied. The substrate, AISI 1045..... More

Abstract
To determine the origin of the inhomogeneous microstructure and texture observed in drawn and annealed high purity copper wires, two kinds of drawing process conditions and their influence was investigated. The regular condition, based on a symmetric die, and a condition designed intentionally to produce an inhomogeneous shear deformation using..... More

Abstract
To understand the effect of microstructural factors (i.e., the size of α phase, equiaxed vs bimodal structure) on high cycle fatigue (HCF) and fatigue crack propagation (FCP) behaviors of mill-annealed Ti-6Al- 4V (Ti64) alloy, three specimens of EQ (equiaxed)–8 (8 indicates the size of α grain), BM (bimodal)-8, and BM-..... More

Abstract
This study investigated the microstructure and room temperature mechanical properties of W-7Ni-3Fe (wt%) tungsten heavy alloy (as-fabricated) which was manufactured by metal injection molding (MIM). To identify the effect of heat treatment on the W-7Ni-3Fe alloy, its properties were compared after heattreatment (1,100 oC for 1 hour) in vacuum atmosphere...... More

Abstract
In this work, we studied the formation of partially stabilized zirconia by a high energy ball milling (HEBM) approach. Zirconia powder was mixed with 8 mol% MgO and the powder mixture was milled for 10 hours. The structural and morphological evolutions of the powder particles were studied using X-ray diffraction..... More

Abstract
The microstructure, tensile properties at room and elevated temperatures, and high-cycle fatigue behavior of an extruded Mg-7Sn-1Al-1Zn (TAZ711) alloy were investigated in comparison with those of an Mg-8Al-0.5Zn (AZ80) alloy extruded under the same conditions. The extruded AZ80 alloy exhibited a fully recrystallized structure, whereas the extruded TAZ711 alloy had..... More

Abstract
Nickel-based superalloys have excellent resistance to extreme environments such as high temperature and high stress and are used as materials for large gas turbines. In this paper, specimens were taken from a blade that had been used for a long time, and their life span was studied by analysis of microstructure...... More

Abstract
To improve the hydrogen uptake and release properties of magnesium (Mg), five weight percent of graphene was added to pre-milled Mg by milling in hydrogen (reaction-involving milling). The hydrogen uptake and release properties of the graphene-added Mg (named Mg-5graphene) were investigated. Premilling of Mg (for 24 h) and then adding..... More

Abstract
This study investigated the effect of Si on the characteristics of FCA multi-layer weld metal with 460 MPa yield strength grade steels for ships and marine structures. The effect on microstructure was evaluated by tensile, charpy impact and CTOD testing of 4 FCAW welds containing various C and Si contents...... More

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