MECHANISM OF STRESS CORROSION FRACTURE OF A COPPER-BERYLLIUM ALLOY

Two basically different stages occur in this process. First, reactions leading to the formation of a crack, then formation and propagation of the crack. In the first stage, dissolution is probably the main effect of the corrosive environment resulting in a preferential attack on grain boundaries or on crystallographic planes. In the second stage, during the formation and propagation of the crack, the amount of plastic deformation, the value of applied stress and distribution of solutes are important. The main effect of the corrosive environment consists in the decrease of the surface free energy by asorption process. Based on these observations a mechanism of stress-corrosion fracture in a copper- beryllium alloy specimen is proposed.