• 대한기계학회논문집
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• 제16권3호
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• pp.485-496
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• 1992

본 연구에서는 제철, 제강공정에서 많이 사용하고 있는 C22FR1.4형의 주형을 상사적으로 축소시킨 주철제(GC25) 주형에 순알루미늄(순도99%)의 주물을 용입하여 응고 및 냉각 과정의 주물 및 주철제 주형에 미치는 열의 영향에 관하여 2차원 비정상 열전도 문제를 경계요소법으로 해석하고 실험을 통하여 검증하였다.

• 디자인학연구
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• 제16권2호
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• pp.291-300
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• 2003

동합금을 이용한 금속공예기법에는 성형기법 세공기법이 있다. 이러한 기법에는 주조기법(Metal casting)과 단금기법이 있는데, 주조기법에는 사형(Sand mould, 토범-중국은 도범, 일본은 물형, 납형), 석형, 안틀 끼우기(입형)와 안틀 깎기(삭중형) 등이 있다. 단금기법에는 단조기법 추기기법, 판금기법 등이 조사되었으며, 세공(장식)기법으로는 조금기법, 선조기법, 점선조기법 등이 조사되었다. 이와 더불어 모조기법, 축조기법, 어자문기법과 세선 세공 및 세입세공을 바탕으로 하는 누금세공기법이 주로 사용 되었음이 밝혀지고 있다. 한국의 전통적인 동합금의 방식에 있어서도 성형기법과 세공기법을 주로 사용하는 특성이 있다. 한국에서는 전통적으로 청동을 사용하여 합금을 시도한 바 있으며, 일본의 경우는 자입착색법을 바탕으로 하는 방식을 주로 하여 제작하며, 중국의 경우는 청동합금기술을 바탕으로 하는 방식을 선호하여 제작하였다. 합금방식에 있어서는 3국 모두 각기 독특한 방식을 사용하고 있으나, 한국의 경우는 청동을 주로 사용하되 현대에 와서는 동합금을 주로 사용하고 일본의 경우는 시부이치와 샤큐도우를 주로 사용하여 착색을 시도하여 그 표현방식이 독특하게 이루어 졌다. 중국의 경우는 동을 사용하되 황동과 백동을 주로 사용하여 특징적인 작품세계를 구축하였다.

• 보존과학회지
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• 제37권4호
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• pp.340-356
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• 2021

We have tried the experimental research of lost-wax casting to reconstruct Gilt-Bronze Pensive Bodhisattva; preliminary and reconstruction experiment based on ancient texts. Main object to reconstruct is Korean National Treasure No.83, Gilt-Bronze Pensive Bodhisattva (Maitreya), then we measure alloy ratio and casting method based on the scientific analysis. Other impurities were removed from the base metal components(copper : tin : lead) and their ratio was set to 95.5 : 6.5 : 3 where the ratios for tin and lead were increased by 2.5% each. The piece-mold casting method was used, and piece-mold casting experiments were carried out twice in this study but supplementary research on piece-mold casting was necessary. The microstructure was confirmed to be typical cast microstructure and the component analysis result was similar to that of the prior study. Analysis of the chemical composition is confirmed to copper, tin, lead, and zinc, and the chemical composition of the matrix was 87.8%Cu-7.5%Sn-2.7%Pb-2.1%Zn, and similar to previous experimental research. Also resulted in the detection of small impurity in Zn. Analysis of the mould revealed that the mould was fabricated by adding quartz and organic matter for structural stability, fire resistance, and air permeability. We expect that our research will contribute to provide base data for advanced researches in future.

• 대한기계학회논문집A
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• 제27권8호
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• pp.1371-1379
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• 2003

RP&M (Rapid Prototyping and Manufacturing) is the most appropriate technology for the small-lot production system, because the production cycle is getting shorter owing to various needs of the consumer. In this paper, rapid tooling technology is applied to the casting process. The casting process has the ability to reflect complicated shapes in one process. But it has not been widely used to make a die and mold because of the poor surface quality caused by air bubbles on the surface of the casting product. In this study, the porous casting mold is fabricated from a mixture of plaster and water-soluble binder. The porous casting mold can improve the characteristics of casting products with the help of the vacuum sealed casting process. The vacuum sealed casting process is an advanced technology that removes the air bubbles between the porous casting mould and the liquid metal, thus making the surface of the casting product finer. The purpose of this paper is to develop a high quality shoe mold using porous casting mold and to apply the RP&M technology to the shoe industry.

• 한국재료학회지
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• 제22권6호
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• pp.309-315
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• 2012

Metal foam has many excellent properties, such as light weight, incombustibility, good thermal insulation, sound absorption, energy absorption, and environmental friendliness. It has two types of macrostructure, a closed-cell foam with sealed pores and an open-cell foam with open pores. The open-cell foam has a complex macrostructure consisting of an interconnected network. It can be exploited as a degradable biomaterial and a heat exchanger material. In this paper, open cell Mg alloy foams have been produced by infiltrating molten Mg alloy into porous pre-forms, where granules facilitate porous material. The granules have suitable strength and excellent thermal stability. They are also inexpensive and easily move out from open-cell foamed Mg-Al alloy materials. When the melt casting process used an inert gas, the molten magnesium igniting is resolved easily. The effects of the preheating temperature of the filler particle mould, negative pressure, and granule size on the fluidity of the open cell Mg alloy foam were investigated. With the increased infiltration pressure, preheat temperature and granule sizes during casting process, the molten AZ31 alloy was high fluidity. The optimum casting temperature, preheating temperature of the filler particle mould, and negative pressure were $750^{\circ}C$, $400-500^{\circ}C$, and 5000-6000 Pa, respectively, At these conditions the AZ31 alloy had good fluidity and castability with the longest infiltration length, fewer defects, and a uniform pore structure.

• 대한치과기공학회지
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• 제2권1호
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• pp.21-24
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• 1980

This experiment was intended to obtain a prefect casting body the same as the original wax patterns by melting metal into the opening of the ring. The investment ring was dried to the temperature between 600 and 700, when the wax pattern would be completely melted to leave an empty mould made in the ring. The main point to studied was the investing process for perfect casting body. This process was experimented on several important factors: the size and spatulation of investment particles, purity of wax patterns, investing time after the completion of model, and investing temperature. The results obtained from the above experiment were as follows: A desirable cast body with no fissure or pore would be mode by investing with smaller particles in the first time and with larger onces in the second, both at the temperature between 180.

• 연구논문집
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• 통권29호
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• pp.163-171
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• 1999

A new titanium alloy system. Ti-xFe-ySi (x,y=0-4 wt%). was designed and characterized with the point at low cost and high strength for casting applications. Fe improved room and elevated temperature mechanical properties owing to solid solution hardening and beta phase stabilization. Si yielded titanium silicides and Si addition over 1 wt% resulted in poor ductility due to coarse silicide chains at prior beta boundaries. The optimum composition was found to be Ti-4Fe-(0.5-1)Si in the viewpoint of tensile strength and ductility which are comparable to the Ti-6Al-4V. The metal-mould reaction was also examined for Ti-xFe and Ti-xSi binary alloy system. The thickness of surface reaction layer w as not affected significantly with Fe content, while it was decreased with Si content. In the Ti-4Si alloy, no reaction layer was found. The depth of surface hardening layer was about $200\mum$ regardless of the mould materials.

• Design & Manufacturing
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• 제7권1호
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• pp.45-49
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• 2013

Since the shell-molds are used to make casting the metal parts for the automobile industry, the quality may well be inconsistent with the lower productivity, increasing the cost of the end products. The primary elbow design shell molded steel castings being produced through extrusion process has $180^{\varnothing}$ O.D., $150^{\varnothing}$ I.D., 14mm thickness and 400mm length, while being processed onto the left side of the tubing. The primary cause for the poor processing is the uneven manual shell molding. If the manual shell molds should be produced to have even quality, they would not be processed for tube linking. The purpose of this study was to develop the flask-molds for manufacturing of the shell molds to ensure mass-production, consistent quality, ommission of processing and comfortable working environment. For this purpose, four flask-molds were produced and thereby, four shell molds were assembled. In particular, the shell molds for processing were formed of the fine coated sand to be blown. As a result, productivity increased about three times, while a consistent quality was ensured. Furthermore, the tubes could be linked with each other without being processed, while pallets could be stacked, stored, transported and managed more easily. In a nut-shell, the molding theory could be applied more effectively. However, it is conceived that this study should be followed up by future studies which will research into reliability and endurability of the end products.

• 보존과학회지
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• 제30권3호
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• pp.263-275
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• 2014

천마총(황남동 제 155호 고분)에서 출토된 철부(鐵釜)의 제작기법 및 보존처리에 대하여 연구하고자 하였다. 철부의 제작기법을 조사하기 위하여 유물 중 일부를 채취하여 마운팅 후 연마하고, etching을 실시하여 금속조직을 관찰하였고, 비금속개재물부분은 SEM-EDS로 분석을 실시하였다. 금속학적 조직검사와 SEM-EDS분석 결과 철 솥은 백주철 조직이 관찰되었고, 주조 후 상온에서 서서히 건조시킨 것으로 보이며, 취성을 개선하기 위해 별다른 열처리를 시도한 흔적은 보이지 않는다. 몸통 중심부의 폭3cm 두께 1.5cm 전이 확인됨에 따라서 가로식 거푸집을 활용한 이분제작기법을 사용하여 주조한 것으로 추정된다. 이처럼 백주철 조직과 가로식 거푸집을 활용한 제작기법은 비슷한 시기인 식리총과 황남대총에서 출토 된 철 솥에서도 나타나는 것으로, 당시 주조품의 생산기술이 동일하였음을 알 수 있었다. 보존처리는 크게 처리전조사, 이물질제거, 탈염처리, 강화처리, 접합 복원, 색맞춤의 순서로 진행하였으며, 처리과정 중 필요에 따라 세척 및 건조를 실시하였다. 강화처리는 유물의 크기로 인하여 진공함침에 어려움이 있었으므로, 저농도의 Paraloid NAD-10을 2-3차례 붓으로 도포하였고, 보존처리가 완료된 후 15wt.% Paraloid NAD-10용액으로 표면을 재강화하였다. 파손부위의 복원은 섬유강화플라스틱 수지(POLYCOAT FH-245,몰드 적층용)를 사용하여 파손 부위와 유사한 형태의 모형을 만든 후 접합하여 복원하였다. 이번 연구를 통하여 철제유물의 보존처리뿐만 아니라 5-6세기 주조 철솥의 제작기법에 대한 자료를 축적함으로 향후 보다 나은 연구를 위한 발판으로 활용되었으면 한다.