• 한국산업융합학회 논문집
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• 제24권5호
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• pp.597-608
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• 2021

The control head components used in small military vessels are designed to be domestically produced, prototypes, structural analysis, and casting methods are designed and cast. The control head assembly consists of a lever, an aluminum outside cover, Middle, front gear cover, back gear cover, and a zinc worm gear. In order to reverse the design of each component, 3D scanning device was used, 3D modeling was performed by CATIA, and prototype productions were carried out by 3D printer. In order to reduce the cost of components, gating system is used by gravity casting method. The SRG ratio of 1:0.9:0.6 was set by applying non-pressurized gating system to aluminum parts, 1:2.2:2.0 and pressurized gating system to zinc parts, and the shapes of sprue, runner and gate were designed. The results of porosity were also confirmed by casting analysis in order to determine whether the appropriate gating system can be designed. The results showed that all parts started solidification after filling completely. ANSYS was used for structural analysis, and the results confirmed that all five components had a safety factor of 15 more. All castings are free of defects in appearance, and CT results show only very small porosity. ZnDC1 zinc alloy worm gear has a tensile strength of 285 MPa and an elongation of 8%. The tensile strength of the four components of A356 aluminum alloy is about 137-162 MPa and the elongation is 4.8-6.5%.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.131-134
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• 2007

A semi-solid forming technology has a lot of advantages compared to the die casting, squeeze casting and hot/cold forging, so semi-solid forming has been studied actively. Semi-solid forming has two methods. One is thixoforming with reheating of prepared billet, the other is rheoforming with cooled melt until semi-solid state. Thixoforging technology can produce non-dendritic alloys for semi-solid forming complex shaped parts in metal alloys. In this study, the thixoforging was experimented with made rheology materials by the spiral stirrer equipment. Rheology materials for forging were made by A356 casting aluminum alloy and A6061 wrought aluminum alloy. After experiment, forged samples were measured microstructure and were heat treated for high mechanical properties.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.188-194
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• 2001

Metal matrix composites with whisker reinforcements have significant potential for demanding mechanical applications including defense, aerospace, and automotive industries. Especially, metal matrix composites, which are reinforced with aluminum borate whisker, have been used for the part of piston head in automobile because of good specific strength and wear resistance. Aluminum alloy-based metal matrix composites with whisker reinforcements have been produced using squeeze casting method, which is kind of an infiltration method. In this study, AC4CH-based metal matrix composites with $Al_{18}B$_4$O_{33}$ reinforcement have been produced using squeeze casting method, after T6 heat treatment, we evaluated mechanical properties of matrix and MMC composite were evaluated.

• 열처리공학회지
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• 제15권3호
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• pp.136-141
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• 2002

During warm and hot forging process of steels or aluminum alloys, dies are subject to early fracture, severe wear by thermo-mechanical stress. Especially, during the die-casting of aluminum alloys, the service life of dies is incredibly lowered. In this study we investigated the characteristics of TiBN films produced by PECVD. TiBN films showed very high hardness, excellent wear resistance, which could enhance the service life of die parts such as forging punch, die casting core pin successfully.

• 한국주조공학회지
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• 제7권1호
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• pp.28-37
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• 1987

The progression of the solidification wave front in V-section and finned casting was studied by use of the pour-out test, employed with high. Purity aluminum. The results obtained were as follows; a) The shape of solidification wave front at the inside and outside corners did not change according to solidification time, but it changes according to the corner angles at a given molding and melting condition. b) The cooling fin effect could be repserented as functions of solidification time and fin sise, and this result could be applied to enhance the accuracy of the section modulus method in the design of T and V section.

• 한국주조공학회지
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• 제28권5호
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• pp.217-220
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• 2008

본 연구에서는 유한요소법을 적용한 수치해석을 이용하여 타이어 제조용 금형을 생산하기 위해 사용되는 주조재의 열적 특성에 관하여 조사해 보았다. 고 품질의 정밀도가 좋은 타이어를 제조하기 위해, 일반적으로 타이어 제조용 금형의 주조재로 많이 사용되고 있는 알루미늄 합금과 비교 대상으로 연강을 선정하여 각각의 주조재에 대한 응고과정에서의 온도분포와 응력분포 결과를 수치적으로 계산해 보고 결과를 예측해 보았다. 수치해석을 통한 결과에서, 알루미늄 합금을 사용한 금형의 냉각과정 동안의 온도분포는 연강에 비해 보다 더 안정적으로 나타나는 것을 확인하였으며, 응력분포 결과 또한 알루미늄 합금 금형이 연강에 비해 정밀도를 향상시키고 좋은 품질의 제품을 얻는 데 보다 나은 것으로 나타났다. 그리고 금형의 온도분포와 응력분포는 금형의 냉각과정 동안 주조재의 초기 냉각온도에 의해 크게 영향을 받는 것으로 사료된다. 마지막으로, 이러한 수치해석에 의한 금형의 열적 특성 예측은 향후 고품질, 고정밀도의 금형 생산을 위한 예비성능평가 방법과 경제적 측면에서 매우 유용하게 활용할 수 있을 것으로 보인다.

• 소성∙가공
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• 제17권1호
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• pp.5-8
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• 2008

As the semi-solid forming technology has a lot of advantages compared to the die casting, squeeze casting and hot/cold forging, it has been studied actively. This paper focuses on the thixoforging of the rheological materials fabricated by the spiral mechanical stirring equipment with A356 casting aluminum alloy and A6061 wrought aluminum alloy. Formability tests of rheological materials fabricated by spiral mechanical stirring were carried out and the microstructures of forged sample were observed. After thixoforging experiment, the heat-treated conditions of forged samples are investigated to improve the mechanical properties. These results are able to suggest the possibility of commercialization for rheological materials fabricated by spiral mechanical stirring.

• 전기학회논문지
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• 제61권1호
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• pp.70-74
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• 2012

Copper die casting motor (CDM) has a better design flexibility than aluminium die casting motor (ADM) because of the higher conductivity of copper. However, CDM has an economic and manufacturing weak point due to high copper price and high melting temperature compared to ADM. This paper describes a comparison of the design parameters, specifications, performances and material cost between CDM and ADM of 5.5kW_6P.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 고액공존금속의 성형기술 심포지엄
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• pp.135-147
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• 1997

The production of light metal parts using aluminum is mainly performed by die casting and squeeze casting, which directly fabricate the required shape from the liquid state. However, die casting is subject to defects such as shrinkage porosity and air trapped when molten metal enters the cavity, whilst squeeze casting also has defects due to turbulent flow in the die cavity. Both diecasting and sqeeze casting have inhomogeneous mechanical property in terms of dendritic structure during solidification. Active research has been carried out on semi-solid processing, rather than on conventional process methods such as die casting, which involve various problems. Therefore in this paper, to introduce the fundamental technology for d e design, in die casting and forging process with semi-solid materials, relationship between stress and strain of semi-solid materials, and for producing parts die design has been proposed as parameters of globulization of the microstructure and gate shape. The prevention of various defects to produce sound parts are also introduced.

• 한국주조공학회지
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• 제38권3호
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• pp.55-59
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• 2018

To optimize the conductivity and to reduce the weight by as much as possible, Al-Cu composites were prepared through a suction-casting procedure. Pure copper metal foam was infiltrated by melted aluminum with the use of the vacuum, after which warm rolling was conducted to remove several remaining pores at the interface between the Cu foam and the aluminum matrix. Despite the short casting time, significant dissolution of Cu into the melt was observed. Moreover, it was found that various Al-Cu intermetallic compounds arose at the interface during the isothermal heating process after the casting and rolling steps. The average thickness of the Al-Cu intermetallic compound tended to increase in proportion to the heating time. The electrical and thermal conductivity levels of the cast composites were found to be comparatively low, mainly due to the dissolution of the Cu foam and the formation of intermetallics at the interface.