• Title/Summary/Keyword: Forming Parameter

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The Effect of Forming Parameter on Mechanical Properties in Hot Bending Process of Boron Steel Sheet (보론강판의 열간 벤딩 공정에서 성형인자가 기계성질에 미치는 영향)

  • Kwon, K.Y.;Sin, B.S.;Kang, C.G.
    • Transactions of Materials Processing
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    • v.19 no.4
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    • pp.203-209
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    • 2010
  • In the hot press forming process (HPF), a martensitic structure is obtained by controlling the cooling rate when cooling a boron sheet that is heated up to over $900^{\circ}C$. The HPF process has various advantages such as the improvement in formability and material properties and minimal spring back of the deformed materials. The factors related to the cooling rate depend on the heat transfer characteristics between heated materials and dies. Therefore, in this study, the cooling rate is controlled by adjusting the heat transfer coefficient of the material at the pressing process. And, the mechanical properties and microstructure of the deformed material is demonstrated during the HPF process where cold dies are used to form the heated steel plate. This is achieved by varying the major forming conditions that control the cooling rate regarded as the most important process parameter.

A New Cu-Hf-Al-Be Bulk Amorphous Alloy with High Glass Forming Ability (우수한 비정질 형성능을 가지는 Cu-Hf-Al-Be 4원계 벌크 비정질 합금)

  • Shin, Sang-Soo;Lim, Kyoung-Mook;Kim, Seong-Nyeong;Kim, Eok-Soo
    • Journal of Korea Foundry Society
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    • v.31 no.4
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    • pp.186-190
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    • 2011
  • A new Cu-Hf-Al-Be monolithic bulk amorphous alloy was developed utilizing minimal use of toxic and expensive Be. The developed alloy exhibits a large glass forming ability (GFA) (${\Phi}8$ mm). The possible mechanisms underlying the enhancement of the glass forming ability by this alloy are discussed based on the dimensionless parameter ${\gamma}$. In addition, alloy design strategy for the improvement of GFA is proposed in the viewpoint of heat of mixing (${\Delta}H_{mix}$)difference and atomic packing state.

Numerical and Experimental Investigation on the Tube Forming in the Radial-Forward Extrusion

  • Ko Beong-Du;Jang Dong-Hwan;Choi Ho-Joon;Hwang Beong-Bok
    • International Journal of Precision Engineering and Manufacturing
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    • v.6 no.2
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    • pp.26-33
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    • 2005
  • In this paper, the tube forming by radial-forward extrusion is analyzed by numerical simulation and experiments. The paper discusses the effect of process variables such as gap height, relative gap width and die comer radius on tube forming. The influence of deformation patterns of flange in radial extrusion on forward extrusion for tube forming is investigated and summarized in terms of the maximum forming force and hardness variations along the extrusion path. Furthermore the external defects are shown experimentally during the forming operation. Based on finite element analysis in conjunction with experimental test in Al alloy, analysis is performed for important parameter combination in order to reduce forming defects. Eventually, the process parameters for safe forming are suggested in order to reduce the forming defects.

Numerical and Experimental Investigation on the Tube Forming in the Radial-Forward Extrusion (레이디얼-전방압출에서 튜브성형에 관한 해석 및 실험)

  • 고병두;장동환;최호준;황병복
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.12
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    • pp.168-175
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    • 2003
  • In this paper, the tube forming by radial-forward extrusion is analyzed by numerical simulation and experiments. The paper discusses the effects of process variables such as gap height, relative gap width and die corner radius on tube forming. The influence of deformation patterns of flange in radial extrusion on forward extrusion for tube forming is investigated and summarized in terms of the maximum forming force and hardness variations along the extrusion path. Furthermore the external defects are shown experimentally during the forming operation. Based on finite element analysis in conjunction with experimental test in Al alloy, analysis is performed for important parameter combination in order to reduce forming defects. Eventually, the process parameters for safe forming are suggested in order to reduce the forming defects.

Design of the Radial Extrusion Process for the General-Purpose Flange Using Model Material (모델재료를 이용한 범용 플랜지의 레이디얼 압출 공정설계)

  • Lee, Sang-Don;Byon, Sung-Kwang
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.2
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    • pp.114-120
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    • 2008
  • This study is to compare and analyze the material flow, deformation characteristics, and forming load of flange by means of similitude experimental method of model material using plasticine. In order to find optimal forming conditions, prototype experiments were designed to investigate forming characteristics of general-purpose flange under various working conditions. As a result of prototype experiments, billet thickness and gap-height ratio was found to be the most influential experimental parameter in flange forming. Forming loads from prototype experiments were compared to the results of finite element analysis after conducting estimation of forming loads of real material. Results of prototype experiments based on model material techniques are expected to be used as a basic data of die design f3r the development of products and process.

A Fundamental Study on Magnetic Pulse Forming with Bar Forming Coil (Bar 성형 코일을 이용한 전자기 성형에 관한 기초 연구)

  • Shim, Ji-Yeon;Kang, Bong-Yong;Park, Dong-Hwan;Kim, Ill-Soo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.3
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    • pp.292-297
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    • 2011
  • MPF(Magnetic pulse forming) process refers to the high velocity and high strain rate deformation of a low-ductility materials driven by electromagnetic forces that are generated by the rapid discharge current through forming coil. The goal of this study was to find the characteristics of dynamic behavior of workpiece and to find the main design process on MPF using bar forming coil. For these purposes, thin Al5053 sheet were used for the experiment. The measured strain data were analyzed by developed electromagnetic FE-model. The main design parameter is location of coil, electromagnetic force. In case of the bar forming coil, there exists the dead regions where the low electromagnetic force applied on the workpiece.

Micro-Deformation of Tows According to Foam Density and Shear Angle During Hemisphere Draping Process (반구형 드레이핑 공정 중 포움의 밀도와 전단각에 따른 토우의 미세변형)

  • Chung Jee-Gyu;Chang Seung-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.7 s.250
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    • pp.849-856
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    • 2006
  • In this paper, fabric composite draping on hemisphere moulds were studied to find out the deformation behaviour of micro-tow structures of fabrics during draping and thermoforming. Aluminium and PVC foams were used to fabricate the hemisphere moulds for draping tests. In order to observe the local tow deformation pattern during the draping several specimens for microscopic observation were sectioned from the draped hemisphere structures. The effect of forming condition and mould properties on tow deformation was investigated by the microscopic observation of the tow parameters such as crimp angle. Normalization scheme was performed to compare tow parameter variations with different forming conditions. Stress-strain .elations of two different PVC foams (HT70 and HT110) were tested to investigate the effect of foam property on the micro-tow deformation during forming.

Prediction and Evaluation of Drawbead Restraining Force with Finite Element Analysis (유한요소해석을 통한 드로우비드 저항력의 예측 및 평가)

  • Bae G. H.;Song J. H.;Kim S. H.;Kim D. J.;Huh H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.87-90
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    • 2005
  • The drawbead is used to control the material flow into the die and increase the forming quality during the binder wrap process and the stamping process in the sheet metal forming. Drawbead restraining force (DBRF) is controlled by geometrical parameters and influenced by process parameters such as friction coefficient and blank thickness. In order to inspect the effect of process parameters, parameter studies are performed with the variation of parameters using finite element model of drawbead which is utilized reliably for the calculation of the drawbead restraining force. Drawbead analysis is carried out with 2-D plane-strain element and 3-D shell element. After the verification of the accuracy of the drawbead model with 3-D shell element, it is utilized to the prediction and the investigation of the effect of process parameters. The result of parameter studies can be utilized to the die design in the tryout stage.

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Optimal Blank Design for Sheet Metal Stamping (박판성형공정의 블랭크 최적설계)

  • 김용환
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.04a
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    • pp.141-145
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    • 2000
  • A systematic method to find the optimal blank shape for sheet forming is proposed by coupling the numerical simulation technique. A weighted parameter was introduced in order to simplify the multi-variable optimization problem to a single-variable problem. The proposed method has been applied to the blank design of drawing processes to obtain the near-net shape within the required error bound after forming, Excellent results have been obtained between the numerical results and the target contour shapes. Through the investigation the proposed systematic method for optimal blank design is found to be effective in the practical forming processes

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Material Test and Forming Analysis of Urethane Rubber (우레탄 고무에 대한 물성평가 및 성형해석)

  • Woo, Chang-Su;Park, Hyun-Sung;Lee, Geun-An
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.279-284
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    • 2007
  • Elasto-forming has been dedicated to specific and limited production. Today, using enhanced pad materials, it has become an efficient and economical process alternative for low and medium volume metal-forming production. The non-linear properties of elastomer which are described as strain energy function are important parameter to design and evaluate of elastomer component. These are determined by material tests which are uni-axial tension and bi-axial tension. In order to investigate the design paramerer, Finite element analysis was carried out for elasto-forming process.

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