http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
박흥일 ( Heung Il Park ) 한국주조공학회 2003 한국주조공학회지 Vol.23 No.1
N/A This experimental study was carried out to investigate the solidification characteristics of polystyrene added styronaphthalene pattern materials using various castability test methods. The styronaphthalene showed an excellent filling capacity and shaping behavior having about 0.2 mm meniscus radius. The shell thickness of styronaphthalene showing smooth wall at the solid/liquid interface increased with the increasing of polystyrene addition. The solidification microstructure of styronaphthalene showed a typical thin ribbon reinforced composite structure, which has fibrous amorphous skeleton of polystyrene and crystalline naphthalene. From the results of this study, it was found that the polystyrene added styronaphthalene showed a precision shaping behavior as disposable pattern material under the atmospheric condition.
무연 Cu-Zn-Sn 청동의 조직과 주조성에 미치는 Bi 및 Sb 첨가의 영향
박흥일 ( Heung Il Park ),박성익 ( Sung Ik Park ),김성규 ( Sung Gyu Kim ) 한국주조공학회 2012 한국주조공학회지 Vol.32 No.2
The effects of Bi and Sb additions on the microstructures and casting properties in lead-free Cu-Zn-Sn broze were investigated. (1) When only Bi was added to the bronze, Bi was precipitated on the δ phase of α dendrite cell boundary. When Bi and Sb were added together, Bi was precipitated on the δA which was the Sb-rich area in the δ phase. (2) The addition of Sb accelerated the formation of δ phase, and when Sb, Bi and Pb were added, Bi and Pb were precipitated as mixed solution in the δA phase. (3) The combined addition of Sb and Bi resulted in the suppression of shrinkage due to the complementary effects of the mass feeding of α- dendrite cluster covered with δ phase and sealing of micro-shrinkage in the δ phase by solidification expansion of Bi.
박흥일 ( Park Heung Il ),김지태 ( Kim Ji Tae ),김우열 ( Kim U Yeol ) 한국주조공학회 2003 한국주조공학회지 Vol.23 No.5
N/A The aim of this study is fabricating of composite filler metal (CFM) by a combination of selective laser sintering (SLS) of stainless steel powders (RapidSteel 2.0^(™) and liquid phase infiltration of Ag-28 wt. %Cu alloy. Porous stainless steel body with inter-connected pore channels was fabricated by SLS, binder decomposing and densification processes. By the direct contact infiltration, the narrow inter-particle channels of the porous body were completely filled with the Ag-28 wt. %Cu alloy infiltrant. During infiltration, the dissolved elements of Fe, Ni and Cr from the porous body were solved into copper solid solution phases, which consist of eutectic structure of composite metal matrix. The S10C/CFM/S10C joints, which have narrow clearance gaps between them up to 10 micrometers, were joined successfully by self- feeding of filler metal from the matrix of CFM. The CFM kept its original thickness and microstructure after brazing. The tensile strength of brazed specimen was higher than 30 kgf/㎟ and showed a typical ductile fracture mode in the CFM.
박흥일,배차헌 ( Heung Il Park,Cha Hurn Bae,Siegfried Engler ) 한국주조공학회 1991 한국주조공학회지 Vol.11 No.2
N/A The purpose of this paper is to describe the solidification characteristics and the formation mechanism of in-situ composite structure with multilayer in the hypereutectic gray cast iron preform produced by centrifugal atomized spray casting process. The experimental work has been carried out in dry air atmosphere in the spray chamber. With increasing the thickness of preform, the solidification structure changes from a typical spray deposition structure with the splat boundaries to a typical spray casting structure without the splat boundaries. The effectiveness and the density of graphite nucleation, and the kinetics of growth of graphite should be higher on the interface of splats than the inner portion of splat. Consequently, graphite nucleates and grows preferentially on the interface of splats, and these splats are self-bonded tightly by the growth of graphite. The solidification mode of each splat showed the latest solidified zone in the center of splat, and these splats were consolidated with the unit component of in-situ composite structure which consists of the layer of graphite colonies, the layer of ferritic and pearlitic matrix, and the layer of segregated phase such as phosphides.
박흥일,김명호 ( Heung Il Park,Myung Ho Kim ) 한국주조공학회 1986 한국주조공학회지 Vol.6 No.4
The effects of copper as an alloying element on the microstructure of Compacted Vermicular graphite cast iron which was treated with Mg-REM spheroidizer have been studied. With the increase of copper content up to 2.0wt%, the following results were obtained; First, the ratio of residual magnesium content in the as-cast iron has been found to be increased, possibly due to the decrease of sulfur content in the melt. Thus, the morphology of graphite in the as-cast iron has been found to be more nodular type. Second, the proportion of pearlite in the matrix has been found to he increased, however the matrix being with free carbide precipitates in the copper range of 1.2wt.% to 2.0wt.%. Third, the tensile strength of the as-cast iron in the temperature up to 400℃ was increased.