The effect of reinforcement particle size (3 and 14 μm), matrix-to-reinforcement particle size ratio (PSR) ranging from 2.9 to 12.9 and volume fraction of the reinforcement (0 20 vol.%) on microstructure and mechanical properties (yield stress, tensile strength, elongation to fracture and Young's modulus) is investigated for Al 6Cu 0.4Mn⧹SiCp composites manufactured by the powder metallurgy route.
It was found that the profiles and total variations of the L, T and N components of the total residual stress are dominated by those of the macroscopic residual stress in the matrix, and by those of the elastic mismatch residual stress in the reinforcement, revealing a significant load transfer from the matrix to the reinforcement.
This contributes to stress transfer from matrix to CNT reinforcement and consequently to enhancement of mechanical properties of the composites.
This critical length enables maximum stress transfer from the resin matrix to fiber reinforcement [ 24] and also makes each fiber to behave as individual crack stoppers [ 25].
(3) The degree of interconnectivity of the rigid phases: this can result in an extra increase of load transfer from matrix to the reinforcement which is more important at high temperatures where the matrix gets softer [30].
This strengthening effect is quantitatively explained in both the Newtonian and non-Newtonian regimes, and is found to arise from two contributions: (i) load transfer from the amorphous matrix to the reinforcements; and (ii) a shift in the glass structure and properties upon precipitation of the reinforcements.
Appreciable improvement was observed in damping, tensile, and impact properties of the polymer matrix due to reinforcement with superelastic SMA fibers, highlighting the advantages of their use in polymer composites.
Tensile fracture mechanism of the composites is primarily controlled by particle cracking as a result of effective load transfer from matrix to the reinforcements.
Addition of 6% (wt/wt) of MAPP resulted in a significant enhancement in the tensile strength in line with the improvement of the fiber matrix interfacial adhesion making more effective the transfer of stress from the matrix to the rigid reinforcement.
Due to poor load transfer from the matrix to the CNT, the reinforcement effect attributed to the CNT is negligible; hence the interphase is regarded as the only reinforcement phase in the composite.
