Exudation of Material from Slip Bands at the Surface of Fatigued Crystals of an Aluminium–Copper Alloy

No satisfactory explanation of the fatigue mechanism of metals has yet been advanced. The generally accepted idea involving work-hardening and subsequent ‘brittle’ fracture cannot be substantiated by observation as being the only cause of fatigue failure. Observations I have made on pure aluminium and aluminium–½ per cent silver specimens have shown that the mechanisms of failure at high and low stresses are fundamentally different1.