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        검색결과 10

        2.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to investigate the effect of an aluminum chromium nitride (AlCrN) coating on tool wear and hole quality in the conventional drilling process of carbon fiber-reinforced plastic (CFRP) composites, titanium alloy (Ti), and CFRP–Ti stack workpieces popular in the aerospace industry. The advanced arc plasma acceleration (APA) method of physical vapor deposition (PVD) was used for all AlCrN coatings. The drilling experiments were conducted with uncoated drills as well as AlCrN-coated drills. When drilling CFRP only, the AlCrN coating was removed at the drill cutting edges and the margin area, which suggests the carbon fibers abraded the coatings. When drilling Ti only, the AlCrN-coated drill mitigated the Ti adhesion formation, which resulted in less tool wear. In addition, hole quality for both CFRP and Ti was improved when the coating was used versus the uncoated tool. The machinability of CFRP–Ti stacks in the drilling process was improved by utilizing the advanced AlCrN coating on the WC tool in terms of drilling forces and hole quality parameters such as average hole size, average hole roundness, hole surface roughness, and Ti exit burr height.
        4,200원
        3.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ti-based alloys are widely used in biomaterials owing to their excellent biocompatibility. In this study, Ti- Mn-Cu alloys are prepared by high-energy ball milling, magnetic pulsed compaction, and pressureless sintering. The microstructure and microhardness of the Ti-Mn-Cu alloys with variation of the Cu addition and compaction pressure are analyzed. The correlation between the composition, compaction pressure, and density is investigated by measuring the green density and sintered density for samples with different compositions, subjected to various compaction pressures. For all compositions, it is confirmed that the green density increases proportionally as the compaction pressure increases, but the sintered density decreases owing to gas formation from the pyrolysis of TiH2 powders and reduction of oxides on the surface of the starting powders during the sintering process. In addition, an increase in the amount of Cu addition changes the volume fractions of the α-Ti and β-Ti phases, and the microstructure of the alloys with different compositions also changes. It is demonstrated that these changes in the phase volume fraction and microstructure are closely related to the mechanical properties of the Ti-Mn-Cu alloys.
        4,000원
        4.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is conducted as a preliminary research to verify the feasibility of Ti-based Oxide dispersion strengthened (ODS) alloy. Pure-Ti powder is mixed with Y2O3 powder and subsequently, mechanically alloyed at -150oC. The Ti-based ODS powder is hot-isostatically pressed and subsequently hot-rolled for recrystallization. The microstructure consists of elongated grains and Y excess fine particles. The oxide particle size is larger than that of the typical Febased ODS steel. Tensile test shows that the tensile ductility is approximately 25%, while the strength is significantly higher than that of pure Ti. The high-temperature hardness of the Ti-ODS alloy is also significantly higher than that of pure Ti at all temperatures, while being lower than that of Ti-6Al-4V. The dimple structure is well developed, and no evidence of cleavage fracture surface is observed in the fracture surface of the tensile specimen.
        3,000원
        5.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        One-dimensional rutile TiO2 is an important inorganic compound with applicability in sensors, solar cells, and Li-based batteries. However, conventional synthesis methods for TiO2 nanowires are complicated and entail risks of environmental contamination. In this work, we report the growth of TiO2 nanowires on a Ti alloy powder (Ti-6wt%Al- 4wt%V, Ti64) using simple thermal oxidation under a limited supply of O2. The optimum condition for TiO2 nanowire synthesis is studied for variables including temperature, time, and pressure. TiO2 nanowires of ~5 μm in length and 100 nm in thickness are richly synthesized under the optimum condition with single-crystalline rutile phases. The formation of TiO2 nanowires is greatly influenced by synthesis temperature and pressure. The synthesized TiO2 nanowires are characterized using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HR-TEM).
        4,000원
        6.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to decrease a stress shielding effect shown in the hip joint. To conduct this study, the clad materials were produced by using an explosion welding method with two materials that were different in the elastic modulus like Ti-6Al-4V alloy and pure Ti. As for the clad materials, the Ti-6Al-4V alloy with large elastic modulus was designed as the neck of femur, and the pure Ti with small elastic modulus as the body of femur. The joints of clad materials formed by the explosion welding showed the typical wave shape, and its thickness was about 0.2㎛. New crystal or grain structure was not formed in the joints. In addition, the Vickers hardness in the joints formed the middle value between the base metal and clad metal. As a result of manufacturing prototype by processing the clad materials in three dimensions, this study gained good shape, and if it is to be applied to clinical in the future, this researcher can expect good results. From the result of this research above, it may be summed up as follows. It is considered as the stress shielding phenomenon showed on the hip joint can be decreased to a certain degree if this researcher is to utilize two clad materials with different elastic modulus like Ti-6Al-4V alloy and pure Ti
        4,000원
        7.
        2014.02 구독 인증기관 무료, 개인회원 유료
        In this study, a large modulus of elasticity of the titanium alloy in use, to create artificial hip stress shielding effect appears to reduce the head portion is excellent in the strength of Ti-6Al-4V, making bone pusher which requires low elastic modulus relative modulus of pure titanium grade 2, using a small two metal after welding by explosion welding hip was made. Explosion pressure welding by the welding region with respect to the mechanical properties and the tissue was observed.
        3,000원
        8.
        2006.09 구독 인증기관·개인회원 무료
        Titanium alloys and Titanium alloy-based particulate composites were synthesized using the blended elemental P/M route. First, processing conditions such as the fabrication of master alloy powder were investigated. Ti-6Al-4V, Ti-5Al-2.5Fe, Ti-6Al-2Sn-4Zr-2Mo, IMI685, IMI829, Timetal 1100 and Timetal 62S, and Ti-6Al-2Sn-4Zr-2Mo/ 10%TiB and Timetal 62S/10%TiB were then synthesized using the optimal processing conditions obtained. The microstructures and mechanical properties such as tensile strength and high cycle fatigue strength were evaluated.
        9.
        2006.09 구독 인증기관·개인회원 무료
        Mechanical properties of metal injection molded titanium and titanium alloy parts were investigated in this study. Material powders with low oxygen content and spherical shape were obtained by electrode induction-melting gas atomization which could melt and atomize titanium and titanium alloy bars with no touch on crucible or tundish. Tensile specimens were fabricated from obtained powders by metal injection molding process. Tensile strength of the specimens increases with increasing oxygen content. This result corresponds to a tendency of wrought metal.
        10.
        2006.04 구독 인증기관·개인회원 무료
        The spherical and high quality Titanium fine powder "Tilop" has been produced with gas atomization furnace, Sumitomo Titanium Corporation originally designed. Recently, a new process which can produce Ti-alloy(Ti-6Al-4V) powders by utilizing our gas atomization process, of which raw material is sponge titanium pre-mixed with alloy chips or granules has been also developed. The particle size of gas atomized Ti-alloy powder and the mechanical properties of sintered Ti-alloy compacts prepared by metal injection molding were discussed in this study.