• 한국재료학회지
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• 제15권4호
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• pp.257-262
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• 2005

Nano-sized ZrVFe alloy powders were prepared by the ablation of powder compact in alcobol using a Nd-YAG pulsed Laser. The $Zr_{57}V_{35.}8Fe_{7.2}$ alloy commercially designated as ST707 has long been known as the ideal solution for various vacuum applications. The target for the ablation was sintered pellets of $Zr_{57}V_{35.}8Fe_{7.2}$ alloy powder. The alloy was prepared by arc melting and Hydride-DeHydride method. The ablated powders were mostly circular having fairly large size distribution smaller than 200 nm in all cases. The X-ray diffraction study revealed that the ablated alloy retained the crystal structure of the target alloy. Nevertheless, Fe and V contents in the ablated powder were lower than those in the target alloy. This was believed to result from the high vapour pressures of Fe and V compared to that of Zr. The size of the powders ablated at high energy fluence tends to decrease due at least partly to the breakdown of previously made ones.

• Transactions on Electrical and Electronic Materials
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• 제5권4호
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• pp.153-157
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• 2004

ITO thin films were deposited on PET and soda-lime glass substrates by a dc reactive magnetron sputtering of In-Sn alloy metal target without substrate heater and post-deposition thermal treatment. The dependency of rf-bias voltage and substrate power during deposition processing was investigated to control the electrical and optical properties of ITO films. The range of rf bias voltage is from 0 to -80 V and the substrate power is applied from 10 to 50 W. The minimum resistivity of ITO film is 5.4${\times}$10$^{-4}$ $\Omega$cm at 50 W power and rf-bias voltage of -20 V. The best transmittance of ITO films at 550 nm wavelength is 91 % in the substrate power of 30 W and rf-bias voltage of -80 V.

• 한국재료학회지
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• 제13권4호
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• pp.205-212
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• 2003

RF sputtering process was applied to produce thin hydroxyapatite［HA, Ca10($PO_4$)$_{6}$ $ (OH)_2$films on Ti-6Al-4V alloy substrates. To make a 101.6 mm dia.${\times}$5 mm HA target, the commercial HA powder was first calcinated for 3h at $200^{\circ}C$. A certain amount of the calcinated HA powder was pressed under a pressure of 20,000 psi by the cold isostatic press(CIP) and the pressed HA target was sintered for 6 h at $1,200^{\circ}C$. The effects of different heat treating conditions on the bonding strength between HA thin films and Ti-6Al-4V alloy substrates were studied. Before deposition, the alloy substrates were annealed for 1 h at $850^{\circ}C$ under $3.0${\times}$10^{-3}$ Xtorr, and after deposition, the hydroxyapatite/Ti-6Al-4V alloy thin films were annealed for 1 h at 400, 600 and $800^{\circ}C$ under the atmosphere, respectively. Experimental results represented that the HA thin films on the annealed substrates had higher hardness than non-heat treated substrates before the deposition.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권1호
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• pp.23-27
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• 2003

Structural properties of Cu-Ni alloy films, such as preferred orientation, crystallite size, in-ter-planar spacing, cross-sectional morphology, and electrical resistivity, are investigated in terms of tar-get configurations that are used in the film deposition by means of magnetron co-sputtering. Two different target configurations are considered in this study: a dual-type configuration in which two separate tar-gets (Cu and Ni) and different bias types (RF and DC) are used and a Ni-on-Cu type configuration in which Ni chips are attached to a Cu target. The dual-type configuration appears to have some advantages over the Ni-on-Cu type regarding the accurate control of atomic composition of the deposited Cu-Ni alloy. However, the dual-type-produced film exhibits a porous and columnar structure, the relatively large internal stress, and the high electrical resistivity, which are mainly due to the relatively low mobility of adatoms. The affects of thermal treatment and deposition conditions on the structural and electrical properties of dual-type Cu-Ni films are also discussed.

• 한국군사과학기술학회지
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• 제15권5호
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• pp.712-719
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• 2012

Penetrator with enhanced lateral effect(PELE) is a newconcept projectile, without dynamite and fuze. It consists of high-density jacket, closed at its rear end and filled with a low-density filling material. To study the explosion characteristics of PELE, by AUTODYN-3D code, the calculation models of projectile body and bullet target are established and the process of penetrating aluminum-2024 alloy target of PELE is simulated, and the scattering characteristics after penetrating aluminum-2024 alloy target of PELE are studied by different initial velocity. The explicit finite element analysis of PELE fragmentation was implemented with stochastic failure criterion in AUTODYN-3D code. As expansion of filling, the fragments were obtained velocities and dispersed laterally and further more enhancing the damage area largely. The number and shape of the PELE fragments were different depend on impact velocity and incidence angle of filling which fragment generated during penetration and lateral dispersion process.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1193-1196
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• 2009

Low resistivity interconnection and high-mobility channel are required to realize ultrahigh-definition LCDs such as 4k ${\times}$ 2k TVs. We evaluated fully Cu-based gate and Source/Drain interconnections, consisting of stacked pure-Cu/Cu-Mn layers for TFT-LCDs, and found the underlying Cu-Mn alloy film has superior adhesion to glass substrates and CVD-SiOx films. It was also confirmed that wet etching of the Cu/Cu-Mn films without residues and low contact resistance with both channel IGZO and pixel ITO films can be obtained. It is thus considered that the stacked Cu/Cu-Mn structure is one of candidates to replacing conventionally pure-Cu/refractory metal.

• 한국진공학회지
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• 제9권2호
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• pp.144-149
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• 2000

Cu(4.5at.% Mg) target을 이용하여 sputtering에 의해 증착된 Cu(Mg) alloy박막의 열처리시 형성되는 산화 방지막 MgO의 박막 특성에 영향을 주는 인자에 대해 살펴보았다. MgO 박막의 산화방지 능력 및 막질에 영향을 주는 인자로는 열처리 온도, $O_2$ 압력, Mg 농도 등으로 나타났다. MgO 박막의 두께는 열처리 온도가 증가함에 따라 증가하다 $500^{\circ}C$ 이상에서는 150 $\AA$ 정도의 성장한계두께를 나타내었다. 표면에 형성되는 MgO 박막은 $O_2$압력이 낮을수록, Mg의 농도가 높을수록 치밀한 MgO가 형성되어 산화방지에 우수한 특성을 보였으며 전 열처리 과정인 진공 열처리 공정은 1at.%정도의 낮은 Mg 농도에서도 치밀한 MgO형성에 매우 효과적임이 확인되었다. 본 연구에서 Cu(Mg) alloy박막의 열처리를 통해 낮은 저항의 Cu박막의 형성과 동시에 산화방지에 우수한 특성을 보이는 MgO 박막을 열처리 온도, $O_2$ 압력, Mg 농도 등의 최적조건을 이용하여 얻어질 수 있음을 확인하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.425-428
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• 2009

Aerospace engine application needs to stand high temperature and pressure. Because of its mechanical properties such as high strength at high temperature, Alloy 718 is used aerospace engine application about 80%. But alloy 718's mechanical properties cause some problem to manufacturing profile ring like damage of material and mold. In this study, alloy 718's mechanical properties investigated for knowing its formability and using FE-Simulation for designing profile ring roll process and mold shape. Profile ring rolling processing is designed with "Initial material$\rightarrow$Blank$\rightarrow$Linear Ring$\rightarrow$Profilering". Blank's heating temperature is setting $1100^{\circ}C$ for manufacturing a trial profile ring on the basis of FE-Simulation. As a result of manufacturing alloy 718 profile ring, it is possible to make near target profile shape ring with all of the processing condition which gives in this study.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.149-153
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• 2008

Since magnesium alloy sheets have been employed in industrial field which requires the light weight and thin engineering components, most of researches have been focused on the formability of magnesium ahoy sheet. In warm press forming of magnesium alloy sheet, it is important to control the sheet temperature by heating the sheet in closed die. When forming a commercial AZ31 magnesium alloy sheets which are 0.5mm and 1.0mm thick, respectively, time arriving at target temperature and temperature variation in magnesium alloy sheet have been investigated. Sheet metals were mostly formed in simple shapes such as circular or rectangular. Few studies about forming of complex shapes were reported. Thus, the formability of magnesium alloy sheet for complex shapes is investigated. The process variable for a double sink shape deep drawing with circular and rectangular shape was investigated by varying temperature, velocities, and clearances. Accordingly, temperature, velocities, and clearances suitable for forming were suggested through investigating the thickness variation of the product.

• Current Optics and Photonics
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• 제7권6호
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• pp.714-720
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• 2023

Laser cleaning has the advantages of environmental protection, precision, and high efficiency, and has good prospects for application in removing oxide films on the surface of aluminum alloy. This paper discusses the cleaning threshold and cleaning mechanism of aluminum alloy surface oxide film. A nanosecond pulsed laser was used to remove a 5-㎛-thick oxide film from the surface of 7A04 aluminum alloy, and the target surface temperature and cleaning depth were simulated. The effects of different laser energy densities on the surface morphology of the aluminum alloy were analyzed, and the plasma motion process was recorded using a high-speed camera. The temperature measurement results of the experiment are close to the simulation results. The results show that the laser cleaning of aluminum alloy oxide film is mainly based on the vaporization mechanism and the shock wave generated by the explosion.