Elastic Phase-Strain Distribution in a Particulate-Reinforced Metal-Matrix Composite Deforming by Slip or Creep

The macroscopic load-bearing capability of a composite is directly related to the strain partitioning due to load transfer between the component phases. Using neutron diffraction, the elastic mean phase strains were measured during in-situ loading of a Cu-15 vol pct Mo particulatemetal-matrix composite (MMC) at 25 8C, 300 8C, and 350 8C. The degree of load sharing at each temperature was compared to finite-element (FE) results. The load transfer from the matrix to reinforcement is both qualitatively and quantitatively different at low and high temperatures. When the matrix creeps, load transfer is less effective than when the matrix deforms by slip; also, load transfer at elevated temperatures decreases with increasing applied stress.