• Title/Summary/Keyword: Semi-solid Metal Forming

Search Result 18, Processing Time 0.022 seconds

Fabrication of Semi-solid Materials and Components forming Processes (반용융재료의 제조 및 부품성형공정)

  • Kang, Chung-Gil
    • Transactions of Materials Processing
    • /
    • v.3 no.1
    • /
    • pp.3-17
    • /
    • 1994
  • The semi-solid metal forming for vigorously agitated semi-solid alloys has been widely studied over the last decade. Metal forming processes are now being developed using alloys in the semi-solid state, among them are rolling, forging, extrusion, and die casting. Some of these are now employed commercially to produce a components and are also used to fabricate metal matrix composites. The semi-solid materials can be processed either directly during solidification and for this purpose mechanical stirring was demonstrated to produce a highly solidification. This paper is concerned with the influence of processing parameters on limitations of semi-solid forming.

  • PDF

Reheating Process of Semi-Solid Aluminum Alloy (반융용알루미늄재료의 재가열공정)

  • 강성수;도영진;강충길
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1997.06a
    • /
    • pp.16-27
    • /
    • 1997
  • A semi-solid forming has a lot of advantages compared to the die casting, squeeze costing and convenctional forging, therefore, semi-solid forming process are now becoming of industial interest for the production of metal components and metal matrix composites. However, the material behaviour in the semi-solid temperature range is not sufficiently known although it controls the whole process through forces and geometry evolutions bcause the behaviour of metal slurries is complex. The semi-solid materials(SSM) fabricated under electric-magnetic stirring condition is necessary to be applicate in forming process. A reheating conditions were studied with the reheating time, holing time and reheating temperatures. The microstructure of SSM (which specimen size:d 40${\times}$i60) on condition of heating time 10min and heating temperature 590$^{\circ}C$ is most globular and finest one. The microstructure of SSM(specimen size:d75${\times}$i60) reheated under the three step reheating conditions is most globular and finest.

  • PDF

Fabrication of a Part by Heating and Forming in the Semi-solid State of the SKH51 Material (SKH51의 반응고 상태에서의 가열 및 성형에 의한 부품 제조)

  • Lee, Sang Yong
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.27 no.3
    • /
    • pp.127-132
    • /
    • 2014
  • The semi-solid metal forming process has been applied to realize a near-net shape fabrication of a high speed tool steel. A complicatedly shaped part out of SKH51 was successfully manufactured by introducing pertinent materials, tooling and processing conditions. A SKH51 billet with globular grains was heated at temperatures between 1300 and $1350^{\circ}C$ using high frequency induction heater to get semi-solid microstructure before high rate injection of mushy metal into a die cavity for the forming process. It was necessary to control the preheating of dies between 300 and $400^{\circ}C$ to maintain the homogeneous microstructure during the semi-solid metal forming process. Significant defects such as pores, high fraction of liquid fraction and segregation could be removed from the part by using air vents.

Thixoforging Process of Rheology Materials fabricated by Spiral Mechanical Stirring (나선형 기계 교반 레오로지 소재의 이용한 Thixoforging 공정)

  • Han, S.H.;Jung, I.K.;Bae, J.W.;Kang, C.G.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2007.05a
    • /
    • pp.131-134
    • /
    • 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.

  • PDF

Effect of Reheating Conditions of Semi-Solid Aluminum Alloy on Globular Microstructure (반융용 알루미늄재료의 재가열조건이 구상화 조직에 미치는 영향)

  • Gang, Seong-Su;Gang, Chung-Gil;Do, Yeong-Jin
    • Transactions of Materials Processing
    • /
    • v.7 no.3
    • /
    • pp.215-224
    • /
    • 1998
  • A semi-solid forming has a lot of advantages compared to the die casting. squeeze casting and conventional forging. therefore, semi-solid forming process is now becoming industrial interest for the production of metal components and metal matrix composites. However the material behaviour in the semi-solid temperature range is not sufficiently known although it controls the whole process through forces and geometry evolutions because the behaviour of metal slurries is complex. The semi-solid materials(SSMs) fabricated under electric-magnetic stirring condition is necessary to be applicated in forming process. A reheating conditions were studied with the reheating time holding time and reheating temperatures. The microstructure of SSM(specimen size : d39${\times}$h85) at the condition of heating time 10min and heating temperature 590${\circ}C$ is the most globular and finest one. The microstructure of SSM(specimen size : d76${\times}$h60) reheated under the three step reheating conditions is most globular and finest.

  • PDF

A Filling Analysis on Forging Process of Semi-Solid Aluminum Materials Considering Solidification Phenomena (응고현상을 고려한 반용융 알루미늄재료의 단조공정에 관한 충전해석)

  • 강충길;최진석;강동우
    • Transactions of Materials Processing
    • /
    • v.5 no.3
    • /
    • pp.239-255
    • /
    • 1996
  • A new forming technology has been developed to fabricate near-net shape products using light metal. A semi-solid forming technology has some advantages compared with the conventional forming processes such as die casting squeeze casting and hot/cold forging. In this study the numerical analysis of semi-solid filling for a straight die shape and orifice die shape in gate pattern is studied on semi-solid materials(SSM) of solid fraction fs =30% in A356 aluminum alloy. The finite difference program of Navier-Stokes equation coupled with heat transfer and solidification has been developed to predict a filling pattern and the temperature distribution of SSM. The programdeveloped in this study gives die filling patterns of SSM and final solidifica-tion region.

  • PDF

Effect of Viscosity Variation on Flow Characteristic in Thixoforming Process of Semi-Solid Aluminium Alloys (반용융 알루미늄 합금의 Thixoforming 공정에서 점도의 변화가 유도특성에 미치는 영향)

  • 강충길;이유철
    • Transactions of Materials Processing
    • /
    • v.8 no.2
    • /
    • pp.188-199
    • /
    • 1999
  • Semi-Solid Forming Process(Thixoforming, Rheocasting) is a novel forming process which has some advantages compared with conventional die casting, squeeze casting and hot/cold forging. In this study. Thixoforming process was selected as analysis processing in terms of billet handling and easiness of automation process. The Thixoforming process consists of reheating process of billet, billet handling, filling inot the die cavity and solidification of SSM part. In filling process, two rheology models which were Newtonian and Non-Nettonian model (Ostwald-deWaele)were verified with experimental results. The Ostwald-deWaele model shows the good agreement to the real flow and filling phenomena in die cavity. To give a boost the economical efficiency of Thixoforming process and to ensure the good forming result, reheating device coupled die set was proposed and the initial billet temperature for system that was found from experimental resluts. This study presents an overview of application of numerical analysis for simulation of semi-solid metal forming process to reduce the lead time for development of manufacturing part in industrial field.

  • PDF

Applications of Semi-Solid Forming and its Problems (반용융 성형공정의 응용 및 문제점)

  • 강충길
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1997.06a
    • /
    • pp.135-147
    • /
    • 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.

  • PDF

Fabrication of Metal Matrix Composites and Development of Forming System in Mashy State (반응고법에 의한 금속복합재료의 제조 및 성형 시스템의 개발)

  • 강충길;김현우;김영도
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.3
    • /
    • pp.581-593
    • /
    • 1990
  • A semi-solid alloy in which solid and liquid phase are co-existing is obtained by strirring of Al7075 molten metal. A semi-solid alloy is dependent on the corresponding temperature within the solid-liquid range, and the process parameters should be controlled accurately to obtain the homogeneous semi-solid alloy. The possibility o homogeneous fiber-reinforce aluminum alloy by addition of $Al_{2}$O$_{3}$ short fibers with vigorous agitation was investigated. The billet of composite materials was fabricated by squeeze casting, and homogeneous dipersion state of fibers in billet of fabricated metal matrix composites was observed. A slurry of semi-solid short fiber metal matrix composites is used in the direct rolling process, and this process showed the fabrication possibility of metal matrix composite sheets. The fabricated sheet was tested regarding vickers hardness, elongation and micro-structure. It has become clear that mashy state processing and working are very useful to obtain parts of composites material closed to near net shape.

Semi-Solid Forming of Al-Zn-Mg-Cu Alloy Applying Low-Temperature Casting Process (저온 주조법을 응용한 Al-Zn-Mg-Cu 합금의 반응고 성형)

  • Kim, Jeong-Min;Kim, Ki-Tae;Jung, Woon-Jae
    • Journal of Korea Foundry Society
    • /
    • v.22 no.2
    • /
    • pp.82-88
    • /
    • 2002
  • Al-5.5Zn-2.5Mg-l.5Cu semi-solid slurry was prepared by cooling the liquid metal with a low superheat to a solid and liquid co-existing temperature. Relatively round solid particles could be obtained in the slurry through the simple process. The prepared slurry was deformed into the metallic mold by a press and the mechanical properties of obtained specimens were investigated. Mold filling ability of the alloy slurry was also investigated and compared with that of A356 alloy. Al-Zn-Mg-Cu alloy showed lower mold filling ability than A356 alloy probably because small amount of eutectic phase is present and the heat of fusion generated during solidification is smaller than that of A356 alloy.