Analysis of the creep behavior of silicon carbide whisker reinforced 2124 Al(T4)

Analysis of creep behavior of SiC/Al metal matrix composites based on a generalized shear-lag model

“…By comparing Eq. (A5) with the shear-lag model, 12 the effective aspect ratio of a spherical particle is obtained as of 1.25, which is independent on the direction of loading axis due to the symmetry of a spherical particle.…”

“…12,16 Then the creep deformation of composites is dependent on the effective stress acting on the matrix, which is lower than the applied stress on the composite. The ratio of the effective stress on the matrix to the applied stress on the composite in discontinuous reinforced metal matrix composites can be calculated in Eq.…”

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Morimoto et al 2 found that the higher volume fraction and the larger aspect ratio of reinforcement resulted in an increased creep resistance of SiCw/2124Al composite. Nieh et al 3 found that the creep behavior of SiC/Al composite shows minimum creep rate without showing welldefined steady-state creep region.…”

Mechanical Behavior and Processing of Aluminum Metal Matrix Composites

“…Nardone and Strife [206] examined the effects of stress and temperature on the creep behavior of SiC whisker reinforced 2124 aluminum (T4). They have reported that the stress exponent changes from a low value of 8.4 at 450 K to a high value of 21 at 561 K and that the measured activation energies are much higher than that for self diffusion in aluminum; the activation energy increases from a value of 277 kJ/mole in the temperature range of 423 K -477 K to a value of 431 Id/mole in the temperature range of 547 K -575 K. These experimental results were interpreted in terms of an effective …”

“…Nardone and Strife [206] have suggested that three strengthening mechanisms may contribute to the presence of uo. These are: (a) a high rate of composite hardening at lower testing temperature; (b) load transfer from the matrix to SiC whiskers at all temperatures; and (c) the stress necessary to unlock the dislocations from the reinforcement/matrix interface.…”