Constitutive Models for Final Stage Densification of Powder Compacts with Power-Law Creep Deformation

Power-law 크리프 변형을 따르는 분말 성형체의 말기 치밀화 모델

  • 양훈철 (포항공과대학교 대학원 기계공학과) ;
  • 김기태 (포항공과대학교 기계공학과)
  • Published : 2004.07.01


Constitutive models for final stage densification of metal powder compacts with power-law creep deformation were investigated. The constitutive models were implemented into a finite element program (ABAQUS) by using user subroutine CREEP and, from FEM results, useful densification curves were obtained when hydrostatic and uniaxial stress were applied to the powder compacts at various pressures and temperatures. Because the densification behavior varied as the constitutive models, the equivalent stress surface on each constitutive equation was investigated to analyze the difference of densification behavior.


  1. Helle, A. S., Eastering, K. E. and Ashby, M. F., 1985, 'Hot Isostatic Pressing Diagrams: New Developments,' Acta Metall., Vol. 33, No. 12, pp. 2163-2174
  2. Yang, H. C. and Kim, K. T., 2000, 'Densification Behavior of Ti-6Al-4V Powder Compacts by Hot Isostatic Pressing,' Transactions of the KSME A, Vol. 24, No.2, pp. 394-402
  3. Kwon, Y. S. and Kim, K. T., 1996, 'Densification Forming of Alumina Powder-Effects of Power Law Creep and Friction,' J. Eng. Mat. Tech., Vol. 118, pp. 471-477
  4. Wilkinson, D. S. and Ashby, M. E, 1975, 'Pressure Sintering by Powder Creep,' Acta Metall., Vol. 23, pp. 1277-1285
  5. Abouaf, M., 1988, 'Finite Element Simulation of Hot Isostatic Pressing of Metal Powders,' Int. J. Num. Method. Eng., Vol. 25, pp. 191-212
  6. Duva, J. M. and Crow, P. D., 1992, 'The Densification of Powder by Power-Law Creep During Hot Isostatic Pressing,' Acta Metall. Mater., Vol. 40, No.1, pp. 31-35
  7. Cocks, A. C. E, 1989, 'Inelastic Deformation of Porous Materials,' J. Mech. Phys. Solids, Vol. 6, pp. 693-715
  8. Sofronis, P. and McMeeking, R. M., 1992, 'Creep of Power-Law Material Containing Spherical Voids,' J. Applied Mech., Vol. 59, pp. S88-S95
  9. Ponte Castaneda, P., 1991, 'The Effective Mechanical Properties of Nonlinear Isostatic Composites,' J. Mech. Phys. Solids, Vol. 39, No.1, pp. 45-71
  10. Liu Y. M., Wadley, H. N. G and Duva, J. M., 1994, 'Densification of Porous Materials by Power-Law Creep,' Acta Metall. Mater., Vol. 42, No.7, pp. 2247-2260
  11. Govindarajan, R. M. and Aravas, N., 1994, 'Deformation Processing of Metal Powders: Part II-Hot Isostatic Pressing,' Int. J. Mech. Sci., Vol. 36, No.4, pp. 359-372
  12. Sanchez, E., Ouedraogo, E., Stutz, P. and Dellis, C., 1997, 'Numerical Simulation of Metal Powder Forming by Hot Isostatic Pressing,' Int. Workshop on Modelling of Metal Powder Forming Process, Grenoble, France, 21-23 July, pp. 295-304
  13. Bouaziz, O., Dellis, C. and Stutz, P., 1997, 'Creation of a Material Data File for Modelling Hiping of an Austenitic Stsinless Steel,' Int. Workshop on Modelling of Metal Powder Forming Process, Grenoble, France, 21-23 July, pp. 295-304
  14. Kim, K. T. and Jeon, Y. C, 1998, 'Densification Behavior of 316L Stainless Steel Powder Under High Temperature,' Mat. Sci. Eng. A, Vol. A245, pp. 64-71
  15. Kim, K. T. and Jeon, Y. C., 1998, 'Densification Behavior and Grain Growth of Tool Steel Powder under High Temperature,' Acta Mater., Vol. 46, No. 16, pp. 5745-5754
  16. ABAQUS User's I, II and III Manual, 2001, Ver. 6.2, H.D. Hibbitt, I. Karlsson and E.P. Sorenson, USA
  17. Cocks, A. C. F., 1994, 'The Structure of Constitutive Laws for the Sintering of Fine Grained Materials,' Acta Metall. Mater., Vol. 42, No.7, pp. 2191-2210