Hierarchical Finite-Element Modeling of SiCp/Al2124-T4 Composites with Dislocation Plasticity and Size-Dependent Failure

전위 소성과 크기 종속 파손을 고려한 SiCp/Al2124-T4 복합재의 계층적 유한요소 모델링

  • 서영성 (한남대학교 기계공학과) ;
  • 김용배 (한남대학교 기계공학과)
  • Received : 2011.10.31
  • Accepted : 2011.12.02
  • Published : 2012.02.01


The strength of particle-reinforced metal matrix composites is, in general, known to be increased by the geometrically necessary dislocations punched around a particle that form during cooling after consolidation because of coefficient of thermal expansion (CTE) mismatch between the particle and the matrix. An additional strength increase may also be observed, since another type of geometrically necessary dislocation can be formed during extensive deformation as a result of the strain gradient plasticity due to the elastic-plastic mismatch between the particle and the matrix. In this paper, the magnitudes of these two types of dislocations are calculated based on the dislocation plasticity. The dislocations are then converted to the respective strengths and allocated hierarchically to the matrix around the particle in the axisymmetric finite-element unit cell model. The proposed method is shown to be very effective by performing finite-element strength analysis of $SiC_p$/Al2124-T4 composites that included ductile failure in the matrix and particlematrix decohesion. The predicted results for different particle sizes and volume fractions show that the length scale effect of the particle size obviously affects the strength and failure behavior of the particle-reinforced metal matrix composites.


$SiC_p$/Al2124 Composites;Strain Gradient Plasticity;Finite Element Modeling;Dislocation Punching;Particle-Size-Dependent Failure


Supported by : 한국연구재단


  1. Arsenault, R. J. and Shi, N., 1986, "Dislocation Generation due to Differences Between the Coefficients of Thermal Expansion," Materials Science and Engineering, Vol. 81, pp. 175-187.
  2. Lloyd, D. J., 1994, "Particle Reinforced Aluminum and Magnesium Matrix Composites," International Materials Reviews , Vol. 39, No. 1, pp. 1-23.
  3. Nan, C. W. and Clarke, D. R., 1996, "The Influence of Particle Size and Particle Fracture on the Elastic/Plastic Deformation of Metal Matrix Composites," Acta Materialia, Vol. 44, No.9, pp. 3801-3811.
  4. Suh, Y. S., Joshi, S. P. and Ramesh, K. T., 2009, "An Enhanced Continuum Model for Size-Dependent Strengthening and Failure of Particle-Reinforced Composites," Acta Materialia, Vol. 57, No. 19, pp. 5848-5861.
  5. Suh, Y. S., Kim, Y. B. and Rhee Z. K., 2009, "Strength Analysis of Particle-Reinforced Aluminum Composites with Length-Scale Effect based on Geometrically Necessary Dislocations," Transactions of Materials Processing, Vol. 18, No. 6, pp.482-487.
  6. Shibata, S., Taya, M., Mori T. and Mura, T., 1992, "Dislocation Punching from Spherical Inclusions in a Metal Matrix Composite," Acta Metallurgica et Materialia, Vol. 40, No. 11, pp. 3141-3148.
  7. Ashby, M. F., 1970, "The Deformation of Plastically Non-Homogeneous Alloys," Philosophical Magazine, Vol. 21, No. 170, pp. 399-424.
  8. Taya, M., Lulay, K. E. and Lloyd, D. J., 1991, "Strengthening of a Particulate Metal Matrix Composite by Quenching," Acta Metallurgica et Materialia, Vol. 39, No. 1, pp. 73-87.
  9. Dassault Systemes Simulia, Inc., 2009, Abaqus v. 6.9, Providence, U.S.A.
  10. Hansen N., 1977, "The Effect of Grain Size and Strain on the Tensile Flow Stress of Aluminium at Room Temperature," Acta Metallurgica, Vol. 25, No. 8, pp. 863-869.
  11. Brown, L. M. and Stobbs, W. M., 1976, "The Workhardening of Copper-Silica v. Equilibrium Plastic Relaxation by Secondary Dislocations, Philosophical Magazine, Vol. 34, No. 3, pp. 351-372.
  12. Martin, E., Forn, A. and Nogue, R., 2003, "Strain Hardening Behaviour and Temperature Effect on $Al-2124/SiC_{p}$," Journal of Materials Processing Technology, Vol. 143-144, pp. 1-4.
  13. Zhou, C. Yang, W. and Fang, D., 2000, "Damage of Short-Fiber-Reinforced Metal Matrix Composites Considering Cooling and Thermal Cycling," Journal of Engineering Materials and Technology, Vol. 122, No. 2, pp. 203-209.
  14. Biner, S. B., 1994, "The Role of Interfaces and Matrix Void Nucleation Mechanism on the Ductile Fracture Process of Discontinuous Fiber-Reinforced Composite," Journal of Material Science, Vol. 29, No. 11, pp. 2893-2902.
  15. Chu, C. and Needleman, A., 1980, "Void Nucleation Effects in Biaxially Stretched Sheets," ASME Journal of Engineering Materials and Technology, Vol. 102, No. 3, pp. 249-256.
  16. Hall, J. N., Wayne Jones, J. and Sachdev, A. K., 1994, "Particle Size, Volume Fraction and Matrix Strength Effects on Fatigue Behavior and Particle Fracture in 2124 $Aluminum-SiC_{p}$ Composites," Materials Science and Engineering A, Vol. 183, No. 1-2, pp. 69-80.