Effect of interfacial carbon on adhesion and toughness of gold-sapphire interfaces

The effect of carbon on the interfacial fracture of gold-sapphire bonds is quantified by partitioning the measured fracture energy into the works of adhesion and plastic dissipation. The variation in each quantity with interfacial carbon is independently measured. The strong correlation between interfacial adhesion and plastic dissipation suggests synergistic coupling between crack-tip bond rupture and the surrounding plastic deformation in the metal. Possible origins of the observed sensitivity of adhesion to carbon heat treatment are discussed. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. Ali rights reserved.