Temperature dependency of cyclic deformation behavior of Cu-SiO2 single crystal Original Research Article

Copper single crystal with dispersed sphere SiO2 particles were cyclically deformed at the temperatures between 298 K and 673 K. Cu-SiO2 alloy showed longer life compared with pure copper irrespective of temperature and stress amplitude. This would be due to matrix strengthening not only by dispersion but also by development of cell structures in which the dispersed particles behave as their nodes. At higher temperatures, occurrence of stress relaxation around the Cu/SiO2 interface lowered stress-amplitude dependency of slope (Δε/ΔlogN). The observed easy nucleation of fine voids at the Cu/SiO2 interface seemed not to lower the fatigue strength nor shorten the life.