Study of Cyclic Fatigue Damage in Copper-Aluminum Alloys by Thermal Conductivity Measurements

Low-temperature (4–70 °K)thermal-conductivity measurements have been carried out on two copper-aluminum alloys (copper plus 1 at.% aluminum) which have undergone various stages of fatiguing. From the temperature variation of the lattice component of the measured thermal conductivity, the dominant lattice imperfections introduced by fatiguing were determined. It is found that in the copper plus 1 at.% aluminum alloy, the damage is in the form of dislocation pile-ups. In the copper plus 15 at.% aluminum alloy, the damage is a random distribution of dislocations. This damage is of the same nature as that induced by uniaxial tensile deformation.