Authors: S P Lynch
Publish Date: 1985/09/01
Volume: 20, Issue: 9, Pages: 3329-3338
Abstract
Metallographic and fractographic studies of intercrystalline fracture in highpurity Al6Zn3Mg bicrystals in inert liquid metal and water environments are described The effects of variations in grainboundary microstructure on fracture and the effects of cathodically charging specimens with hydrogen prior to testing in inert environments were also investigated Mechanisms of liquidmetal embrittlement stresscorrosion cracking and preexposure embrittlement are discussed in the light of these results The observations suggest that liquidmetal embrittlement and stresscorrosion cracking generally occur by a plasticflow/microvoidcoalescence process that is more localized than that which occurs in inert environments It is proposed that adsorbed liquid metal or hydrogen atoms weaken interatomic bonds at crack tips thereby facilitating the nucleation of dislocations and promoting the coalescence of cracks with voids
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