Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
권호 표지

Process Analysis for Rheology Forming Considering Flow and Solidification Phenomena in Lower Solid Fraction

저고상율 소재의 유동 및 응고현상을 고려한 레올로지 성형공정해석

  • Jung, Young-Jin (Dept.of Precision Mechanical Engineering, Busan National University) ;
  • Cho, Ho-Sang (Dept.of Precision Mechanical Engineering, Busan National University) ;
  • Kang, Chung-Gil (Dept.of Mechanical Engineering, Busan National University)
  • 정영진 (부산대학교 정밀기계공학과) ;
  • 조호상 (부산대학교 정밀기계공학과) ;
  • 강충길 (부산대학교 기계공학과)
  • Published : 2001.09.01
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Abstract

Two-dimensional solidification analysis during rheology forming process of semi-solid aluminum alloy has been studied. Two-phase fluid flow model to investigate the velocity field and temperature distribution is proposed. The proposed mathematical model is applied to the die shape of the two types. To calculate the velocity and temperature fields during rheology forming process, the earth governing equation correspondent to the liquid and solid region are adapted. Therefore, each numerical models considering the solid and liquid region existing within the semi-solid material have been developed to predict the deflect of rheology forming gnarls. The Arbitrary Boundary Maker And Cell (ABMAC) method is employed to solve the two-phase flow model of the Navier-Stokes equation. Theoretical model on the basis of the two-phase flow model is the mixture rule of solid and liquid phases. This approach is based on the liquid and solid viscosity. The liquid viscosity is pure liquid state value, however solid viscosity is considered as a function of the shear rate, solid fraction and power law curves.

Keywords

References

  1. Flemings, M. C., 'Behavior of Metal Alloys in the Semi-Solid State,' Metallurgical Transaction, Vol. 22A, pp. 957-981, 1991 https://doi.org/10.1007/BF02661090
  2. Pitts, H. E., Atkinson, H. V., 'Thixoforming of 6061 Al Alloy for Automotive Components,' The 5th Int. Conf. on Semi-Solid Processing of Alloys and Composites, pp. 97-104, 1998
  3. Mullins, A. M., Walker, D. J., 'Modelling Solid/Fluid Interactions in a Dendritic Semi-Solid,' The 4th Int. Conf. on Semi-Solid Processing of Alloys and Composites, pp. 104-109, 1996
  4. Barkhudarov, M. R., Bronisz, C. L., Hirt, C. W., 'Three-Dimensional Thixotropic Flow Model,' The 4th Int. Conf. on Semi-Solid Processing of Alloys and Composites, pp. 110-114, 1996
  5. Paradies, C. J., Rappaz, M., Imwinkelried, T. Gabathuler, J. P., 'Simulation of the Pressure Die Casting of A Thixotropic Aluminum Alloy,' The 4th Int. Conf. on Semi-Solid Processing of Alloys and Composites, pp. 115-119, 1996
  6. Burgos, G. R., Alexandrou, A. N., 'Two-Phase Model of Flow of Semi-Solid Materials,' The 5th Int. Conf. on Semi-Solid Processing of Alloy and Composites, pp. 217-224, 1998
  7. Modigell, M., Koke, J., 'Two-Phase Model for Metal Alloys in the Semi-Solid State' The 5th Int. Conf. on Semi-Solid Processing of Alloy and Composites, pp. 317-326, 1998
  8. Kang, C. G., Jung, Y. l., 'Comparison of Single Flow and Two-phase Flow for Numerical Analysis of Semi-Solid Forming Process,' The 7th Int. Conf. on Numerical Methods in Industrial Forming Processes in press, June 2001
  9. Kang, C. G., Kim, Y. D. 'A Finite Element Analysis on the Upsetting Process of Semi-Solid Aluminum Material,' J. of Materials Processing Technology, Vol. 66/1-3, pp. 76-84, 1997 https://doi.org/10.1016/S0924-0136(96)02498-3
  10. Ohnaka, I., Introduction of Compute Heat and Solidification Analysis,' MARUZEN, pp. 167-208, 1985
  11. Kang, C. G., Lee, Y. C., 'Effect of Viscosity Variation on Flow Characteristic in Thixoforming Process of Semi-Solid Aluminum Alloys,' J. of the Korea Society for Technology of Plasticity, Vol. 8, No.2, pp. 188-199, 1999
  12. Metal Handbook 10th Edition, ASM, Vol. 2, pp. 2-19, 1990