Simulation and Experiment on Direct Continuous Casting Process of Lead Frame Copper Alloy

Huang Guojie,Xie Shuisheng,Cheng Lei 한국소성가공학회 2010 기타자료 Vol.2010 No.6

Direct Continuous Casting (D.C.C) is an important method in casting lead frame copper alloy. In this paper, numerical simulation is adopted to investigate the casting process in order to optimize the D.C.C technical parameters, such as the casting temperature, casting speed and cooling intensity. According to the numerical results, the reasonable parameters are that the casting temperature is between 1413K~1413K, the casting speed is between 8m/h~10m/h and the speed of cooling water is between 4.2m/s~4.6m/s. And the depth of liquid-solid boundary is measured in different casting temperature and casting speed by experiments. The results show the actual measurements have a little deviation with the numerical simulation. The results of numerical simulation provide the significant reference to the actual experiments.

컴퓨터 시뮬레이션을 이용한 임플란트 상부 티타늄 구조물의 주조방안

오세욱,이호용,이근우,심준성,Oh Se-Wook,Lee Ho-Yong,Lee Keun-Woo,Shim Jun-Sung 대한치과보철학회 2003 대한치과보철학회지 Vol.41 No.4

Statement of problem : It is difficult to obtain a good titanium casting body using the traditional sprue design because of high melting point of Ti, and the low fluidity and high reactivity of molten Ti. Purpose : A new sprue design for titanium casting bodies needs more trial and error. In order to decrease the number of trial and error, computer simulation(MAGMASOFT, Magmasoft Giessereitechnologie GmbH, Achen, Germany) was used to optimize sprue design in U-shaped implant superstructures. Material and method : Five kinds of sprue were examined for the design of the sprue former for titanium casting: Sprue design A(sprue length 4 mm, rectangular shape, 4 sprues), Sprue design B(sprue length 4 mm. round shape. radius 2 mm, 7 sprues), Sprue design C (sprue length 2 mm, round shape, radius 2 mm, 7 sprues). Sprue design D (sprue length 2 mm, cone shape, large radius 3mm. small radius 2mm, 7 sprues), and Sprue design E( sprue length 2 mm. one unit channel shape). Sprue design F(sprue length 2mm, one unit channel shape) was also examined for the design of the customized sprue former in the Biotan system(Schutz Dental Gmbh, Germany). The casting bodies were taken in Sprue design A, Sprue design D, Sprue design E, and Sprue design F in the Biotan casting system. The numerically predicted defects were compared with the experimental dental castings by the radiographic and sectional view observations. Results : 1. According to the result of computer simulation, turbulence during mold filling was decreased in the sequence of Sprue design F, Sprue design E, Sprue design D, Sprue design C, Sprue design B, and Sprue design A. 2. The calculated solidification time contours indicate that hot spot was moved from the casting body to the sprue button in the sequence of Sprue design A, Sprue design B, Sprue design C, Sprue design D, and Sprue design E. The filling pattern of Sprue design F was similar to that of Sprue design E. 3 The predicted filling pattern shows that less turbulence was found in the customized sprue former than in the standard sprue former. 4. According to the results of the radiographic and cross sectional observations, casting defects less than 1mm were found at the center of a casting body with Sprue design E and Sprue design F. However, larger casting defects of 4mm were found in a casting with Sprue design A. 5. The predicted casting porosity was similar to that of the real casting. Conclusion : One unit channel-type and customized sprue former can be recommended. Further research and developement of various sprue designs using computer simulation in necessary to optimize casting design, in order to reduce the formation of casting defects in implant titanuim super-structures.

전차 파워팩에 적용되는 알루미늄 터보 팬의 주조방안 설계 및 주조 해석에 관한 연구

진철규,이운길,Jin, Chul-Kyu,Lee, Un-Gil 한국산업융합학회 2022 한국산업융합학회 논문집 Vol.25 No.5

In this study, sand casting process was applied to manufacture a large aluminum turbo-type fan used for tank powerpack. To apply the sand casting method, the turbo fan was reverse engineered, and after designing three gating systems, the optimal gating system design was selected by performing casting simulation. In the case of the bottom up-gating system, there is a significant temperature loss of the molten alloy during blade filling. When the molten alloy is completely filled into the sand mold, the blade upper tip and front shroud are below the liquidus temperature. In the case of the top down-gating system, molten alloy scattering occurs, but the temperature loss while the blade is filled is smaller than that of the bottom up type. And after the inflow of molten alloy into the mold is completed, the blade upper tip and front shroud are higher than the liquidus temperature. A sand mold was manufactured with the top down-gating system and the casting process was performed. The fan was made perfectly in appearance without any unfilled parts.

Casting Simulation on the Integrated Twin-Scroll Turbine Housing with Exhaust Manifold

( Ho-jeong Kang ),( Pil-hwan Yun ),( Joo-yong Cheon ),( Hyo-jung Kim ),( Chung-min Kim ),( Jin-young Park ) 한국주조공학회 2017 한국주조공학회지 Vol.37 No.6

In this paper, the casting design of the integrated twin-scroll turbine housing with exhaust manifold using stainless steel is investigated. Due to the complexity in its geometry and the poor castability of stainless steel, it is more crucial to set up the appropriate casting design to avoid casting defects. Gas porosity and shrinkage formation with the changes of gating systems (one- /two-side), riser conditions and pouring temperatures are examined via casting simulation and virtual castings. Simulation results show that two-side gating system produced better quality casting than that of one-side gating system, minimizing the gas content of the castings and it is also verified by X-ray analysis for the virtual castings. For the changes of riser conditions and pouring temperatures in the two-side gating system, it is found that the change of the height of two risers plays an important role in obtaining the best quality by reducing shrinkage defects.

Cut Cell 방법을 활용한 공정별 주조유동해석 적용 연구

최영심 한국주조공학회 2023 한국주조공학회지 Vol.43 No.6

일반적으로 주조품은 복잡한 형상을 가지고 있고 , 한 제품 내에서 두께의 차이가 현저하게 나는 경우가 있어 시뮬레이션을 위한 격자를 생성할 때 어려움이 있다 . 주조 유동은 이상유동으로 수치해석을 할 때 공기와 용탕의 경계면을 추적해야하며 밀도차에의한 압력장 계산에 많은 시간이 소요된다 . 이와 같은 이유로 주조유동해석에는 직교격자가 주로 이용되어왔다 . 그러나 직교격자는형상을 제대로 표현하지 못한다 . 곡면에서 나타나는 계단형상 격자로 인해 모멘텀 손실이 발생하고 이로 인해 용탕의 흐름이 달라질 수 있으며 결과적으로 잘못된 주조 방안 설계를 할 수 있다 . 이를 피하기 위하여 직교격자계에서 형상을 좀 더 정확하게 표현하기 위하여 많은 수의 격자를 생성하여 해석을 한다 . 또는 직교격자계에서 발생하는 문제를 수치적으로 보완하는 Cut Cell 방법을 적용하여 해석하는 방법이 있다 . 본 연구에서는 직교격자계에서 주조유동해석을 할 때 격자수에 따른 해석결과와 Cut Cell 방법을 적용한 해석 결과를 비교하였다 . 또한 주조공정별로 실제제품을 주조유동해석을 하고 공정별로 Cut Cell 방법을 적용한 결과를 고찰하였다. In general, castings often have complex shapes and significant variations in thickness within a single product, making grid gen-eration for simulations challenging. Casting flows involve multiphase flows, requiring the tracking of the boundary between air andmolten metal. Additionally, considerable time is spent calculating pressure fields due to density differences in a numerical analysis. For these reasons, the Cartesian grid system has traditionally been used in mold filling simulations. However, orthogonal grids failto represent shapes accurately, leading to a momentum loss caused by the stair-like grid patterns on curved and sloped surfaces. This can alter the flow of molten metals and result in incorrect casting process designs. To address this issue, simulations in theCartesian grid system involve creating a large number of grids to represent shapes more accurately. Alternatively, the Cut Cellmethod can be applied to address the problems arising from the Cartesian grid system. In this study, analysis results based on thenumber of grid in the Cartesian grid system for a casting flow analysis were compared with results obtained using the Cut Cellmethod. Casting flow simulations of actual products during various casting processes were also conducted, and these results wereanalyzed with and without applying the Cut Cell method.

정밀 주조한 디젤밸브링의 미세수축공 제어에 관한 연구

李在鉉,趙昌龍,金豆炫,崔承柱,徐晟文,Mitchell,Alec 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

Quality of casting is dependent on the degree of casting defecets such as shrinkage. porosity segregation. and etc. In study the sensitivity analysis was carried out to investigate the effect of casting parameters on the thermal history of the casting Prediction of microshrinkage formation within the investment cast diesel valve seal ring was also made by computer simulation using ProCAST™. The calculated thermal history was utilized to get the thermal gradient. the cooling rate and the solidification velocity of the whole casting during solidification In sensitivity analysis. the solidification time of the casting was largely dependent upon the metal pouring temperature and the thermal conductivity of the mould. The microshrinkage formation was closely related to the lower thermal gradient region in the Stellite alloy casting. The G/√R value. called Niyama criterion, successfully predicted the distribution of microshrinkage in the actual investment casting and the critical G/√R value for microshrinkage formation in Stellite alloy casting was found as 2℃⁴min.⁴/㎝ for the diesel valve seal ring.

Fabrication by vacuum die casting and simulation of aluminum bipolar plates with micro-channels on both sides for proton exchange membrane (PEM) fuel cells

Jin, Chul Kyu,Kang, Chung Gil Elsevier 2012 International journal of hydrogen energy Vol.37 No.2

<P><B>Abstract</B></P> <P>Among manufacturing methods for bipolar plates, vacuum die casting is an ideal process because arbitrarily complicated shapes and mass production is possible with a high production rate. We report on the fabrication of bipolar plates with micro-channel arrays on both sides by vacuum die casting for use in proton exchange membrane (PEM) fuel cells. The formability, mechanical properties, and microstructures of samples fabricated under various experimental conditions—molten metal temperature, injection velocity, and vacuum assistance—are investigated, and the experimental and simulation results are compared. The die cavity, which is equal to the bipolar plate area, is 200 mm long, 200 mm wide, and 0.8 mm thick. The active area of the channel is 110 mm × 150 mm, and the total plate thickness is 1.1 mm (the width and depth of the channel are 1 and 0.3 mm, respectively). The cast material used in this study is Silafont-36 alloy (Al–Si–Mg–Mn). Good quality samples with very few casting defects are obtained under the following conditions: molten metal temperature of 700 °C; injection velocities for slow and fast shots of 0.3 and 2.5 m s<SUP>−1</SUP>, respectively; and vacuum pressure of 30 kPa.</P> <P><B>Highlights</B></P> <P>► Aluminum bipolar plates have been fabricated using vacuum die casting. ► Optimal melt temperature for good formability and mechanical properties are 700 °C. ► The higher the injection speed of the high-speed region, the more effective the formability. ► Vacuum die casting is more beneficial in terms of formability than is die casting. ► Vickers hardness of bipolar plate is about 100 Hv which increases to 110 Hv after T6.</P>

Local microstructure-based material performance and damage in design and finite element simulations of cast components

Jakob Olofsson 한국CDE학회 2018 Journal of computational design and engineering Vol.5 No.4

A novel approach to incorporate local microstructure-based material performance into finite element method (FEM) simulations of cast components is presented. By adopting perspectives from natural designs as dinosaur skulls and trees, the discipline-wide approach enables accurate prediction of damage in structures based on a heterogeneous distribution of sub-scale features. It is shown that heterogeneous damage tolerance dictates the performance and failure of cast aluminum, and simulations are compared with experimental results of heterogeneous tensile samples using digital image correlation (DIC). The numerical application of the approach in the industrial product realization process of an industrial cast-ing is demonstrated, and the applicability of the approach to understand the behavior and failure of nat-ural as well as synthetic structures is discussed.

잠수함 마스트 커버의 주조방안설계 및 주조해석

진철규 한국산업융합학회 2023 한국산업융합학회 논문집 Vol.26 No.5

In this study, the sand casting process was applied to design the gating system and perform casting simulation in order to domestically produce the submarine mast cover. Based on simulation results, casting experiments were conducted to produce a soundness prototype. The design concept of the mast cover's gating system was based on the design of bell casting. By arranging eight tower-type gates in a circle at 45° intervals, the flow of melt flowing into each gate was uniform and did not mix with each other, and the velocity of melt was also uniform. The mast cover made of Ni-Al-Bronze alloy has no unfilled parts. However, small porosities and flow marks occurred on the surface in several places. Yield strength and ultimate tensile strength are 279.3 MPa and 675.7 MPa, respectively, and elongation is 21.2%.

모델러와 CAE 를 활용한 최적 금형 방안 설계 기술 개발

임채호(C. H. Lim),곽시영(S. Y. Kwak),조인성(I. S. Cho),황호영(H. Y. Hwang) 한국소성·가공학회 2009 소성가공 : 한국소성가공학회지 Vol.18 No.2

In the casting industry field, a lot of researches have been carried out to maximize soundness and productivity and improve quality of mass produced products. The researches on the optimum mould design by using computer simulation have achieved a lot of accomplishments in the die-casting process especially. Their results are utilized to mass-produce sound products in their field. But there are some difficulties to use the simulation in order to make the design of product and mould. In general, repetitive calculations of computer simulation require much analyzing time in order to make sound design of them. Another difficulty is that only expertise technicians can analyze results of the simulation. In order to solve such a problem, we are building mould design optimization system which consists of knowledge-based module, simulation, optimization module and interactive modeler(it is based on the commercial modeler). By using and interacting between these modules of that system, we can easily make an optimum design of mould and construct the database. This study introduce the general process of the system and connection method between the modules is mentioned above and some examples to apply it to real product.