• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.551-552
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• 2012

• 대한기계학회논문집A
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• 제39권7호
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• pp.687-692
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• 2015

자동차 암레스트의 사출성형과 코팅을 동시에 구현하기 위하여 인몰드 코팅 금형을 설계하였다. 개발된 금형은 하나의 코어와 두개의 캐비티를 포함하고 있으며, 캐비티는 기재 캐비티와 코팅 캐비티로 이루어진다. 코어는 가동측 형판에 부착되었으며, 두개의 캐비티는 고정측 형판에서 슬라이딩하는 평판위에 설치되었다. 2 단계 공정으로 이루어지며 가장 먼저 사출성형된 제품은 슬라이딩 평판에 의하여 2 번째 캐비티로 전달되었다. 기재에 적용된 소재는 PC/ABS 이며, 코팅제로는 2 액형 폴리우레탄이 사용되었다. 코팅제의 토출유량을 변경하면서 실험을 수행하였으며, 주제와 경화제의 믹싱특성을 고찰하였다. 토출유량이 증가함에 따라 믹싱이 더욱 향상되었으며, 주입된 코팅제의 중량이 증가할수록 기재 표면에 발생하는 기포가 감소하였다.

• 한국세라믹학회지
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• 제53권5호
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• pp.541-547
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• 2016

In developing high temperature molds with advantages of the sand and precision (investment) castings, mechanical properties of the mold were improved through homogeneous coating of starting powders with an inorganic binder and improvement of fabrication process. Beads with mullite composition were employed for properties of the mold under high temperature, which was compared with artificial sands. Precursors of silica and sodium oxide were used as starting materials for an inorganic binder to achieve homogeneous coating on the starting powders. Strength was enhanced by the glass phase converted from the inorganic binder through heat treatment process. Also, two kinds of process, wet and dry processes, were incorporated to prepare mold specimens. Consequently, fabrication process of the mold with superior strength and high temperature applicability, compared with the previous molds for sand casting, could be suggested through control of the starting material and enhancement of the vitrification efficiency.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.181-187
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• 2000

This study is object to structural analysis comparison of continuous casting mold. A two-dimensional finite element model was developed to compute the temperature distribution, thermal stress and thermal strain behavior for continuous casting mold. For structural analysis using thermal analysis result from ANSYS. In other to structural analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.200-205
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• 2000

This study is object to thermal analysis comparison of continuous casting mold. A two-dimensional transient finite element model was developed to compute the temperature distribution for continuous casting mold. For thermal analysis using analysis result from ANSYS. In other to thermal analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• 한국주조공학회지
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• 제24권5호
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• pp.281-289
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• 2004

The present study focused on the estimation of the interfacial heat transfer coefficient as a function of the surface temperature of the aluminum casting at the mold/casting interface to investigate the effects of superheat and coating layer. The casting experiments of aluminum into a cylindrical copper mold were systematically conducted to obtain the thermal history during solidification. The thermal history recorded by four thermocouples embedded both in the mold and the casting was used to solve the inverse heat conduction problem using Beck's method. The effects of superheat and coating on the interfacial heat transfer coefficient in the liquid state, during the solidification, and in the solid state were comparatively discussed. In the liquid state, the interfacial heat transfer coefficient is thought to be affected by the roughness of the mold, the wettability of the casting on the mold surface, and the thermophysical properties of the coating layer. When the solidification begins, the air gap forms between the casting and the mold, and the interfacial heat transfer coefficient becomes a function of the air gap as well as surface roughness and the superheat. In the solid phase, it depends only upon the thermal conductivity and the thickness of the air gap. The coating layer reduces seriously the interfacial heat transfer coefficient in the liquid state and during the solidification.

• 한국표면공학회지
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• 제54권5호
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• pp.285-293
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• 2021

High-entropy TiAlCrSiN nano-composite coating was designed to improve mold life for high temperature liquid molding. Alloy design, powder fabrication and single alloying target fabrication for the high-entropy nano-composite coating were carried out. Using the single alloying target, an arc ion plating method was applied to prepare a TiAlCrSiN nano-composite coating had a 30 nm TiAlCrSiN layers are deposited layer by layer, and form about 4 ㎛-thickness of multi-layered coating. TiAlCrSiN nano-composite coating had a high hardness of about 39.9 GPa and a low coefficient of friction of less than about 0.47 in a dry environment. In addition, there was no change in the structure of the coating after the dissolution loss test in the molten metal at a temperature of about 1100 degrees.

• 한국주조공학회지
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• 제5권3호
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• pp.19-26
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• 1985

This study has been carried out to examine into wettability of Cu-5%Sn alloy in $Al_2O_3$, MgO, $SiO_2$ and graphite, respectively and investigated into the change in macrostructure of Cu-5%Sn alloy according to kind and mixing rate of mold-coating. The results obtained from the experiment are summerized as follows; 1. Cu Cu-5%Sn alloy, wettabilities of $Al_2O_3$ and MgO were good, on the other hand, wettabilities of $SiO_2$ and graphite were bad. 2. The fine equiaxed zone was created because of the role of $Al_2O_3$ and MgO as preferential nucleation sites. 3. Notwithstanding change of mixing rate of $SiO_2$ in mold coating the equixed zone was not created. 4. The area of equiaxed zone was varied according to mixing rate in the case of using $Al_2O_3$ and MgO in mold-coating.

• 한국전기전자재료학회논문지
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• 제19권11호
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• pp.1050-1054
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• 2006

There have been intensive and continuous efforts in the field of DLC coating process because of their feature, like high hardness, high elasticity, abrasion resistance and chemical stability and have been applied widely the industrial areas. In this research, optimal grinding condition was investigated using Microlens Process Machine for the development of aspheric glass lens which is to be used for mobile phone module with 3 mega pixel and 2.5X optical zoom, and tungsten carbide(WC) mold cote was manufactured using high performance ultra precision machining and the effects of DLC coating on the form accuracy(PV) and surface roughness(Ra) of WC mold core was evaluated.

• 펄프종이기술
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• 제35권1호
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• pp.19-26
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• 2003

In recent years, numerous studies have been carried out to find out the possible substitution of PE-coated paperboards used in packaging of watery or oily foods. Accordingly, this study was carried out to obtain the basic data for producing higher functional coating agents for pulp mold by evaluating various kinds of mixed coating agents. At that time, two kinds of synthetic coating agents(AKD, PYA) and three kinds of natural coating agent(CMC, corn starch, oxidized starch) were used for making the mixed coating agents respectively. Physical properties of coated paperboards were tested. Conclusions obtained from this study were as follows. Based on concentrations, the proper mixture ratios were 10:90(AKD:CMC), 10:90(AKD:corn starch), 10:90(AKD:oxidized starch), 40:60(PVA:CMC), 20:80(PVA:corn starch) and 20:80(PYA:oxidized starch). The mixed coating agent of PYA:corn starch(20:80) was the most efficient coating agent. Consequently, water and oil resistance were improved even with much addition of natural coating agents. We consider that they can be suitable for the packaging used in the storage of higher moisture vegetables and other food, and also can be suitable for oily fried food.