Abstract
The fatigue behaviors of three dispersion strengthened copper alloys were experimented. The specimens were prepared by ball mill mixing of electrolytic copper powder (-325 mesh) with thoria, alumina or tungsten powder up to 3.0 volume percent, followed by compacting, sintering, hot extruding and cold drawing, and annealed at 600°C for 1 hr in vacuum before testing. For comparison two kinds of pure copper were studied, -one was of the sintered electrolytic copper powder compact and the other of the ingot of vacuum-melted cathode copper. The fatigue tests were performed on an alternating-torsion fatigue machine.
From the experimental results, it has been shown that the fatigue lives of the dispersion strengthened alloys became longer than that of pure copper with an increase in the tensile strength of the alloys. The alloy containing alumina had a little longer life than pure copper. For the alloys containing a dispersed phase of 3.0 volume percent, the microscopic change of surface was observed during fatigue testing.
