Fatigue Studies of Non-Ferrous Sheet Metals

The paper describes the development of a fatigue test machine for sheet metals and gives results of fatigue tests on five alloys of alpha brass, one alloy of nickel silver, one alloy of phosphor bronze and Everdur. The results indicate that cold work raises the endurance limit but not proportionally to the increase in tensile strength produced by the same cause. Micrographs are shown indicating that fatigue failure of the metals investigated is transcrystalline. Dispersion hardening of alpha brass by nickel silicide increases the endurance limit. The ratio of endurance limit to ultimate tensile strength of these alloys varies from .12 to .36 depending on composition, heat treatment, and cold work. These ratios are much lower than similar ratios for steel.