DIFFUSION BONDING OF AN ALUMINUM-LITHIUM ALLOY (AA8090) USING ALUMINUM-COPPER ALLOY INTERLAYERS .1. MICROSTRUCTURE

Diffusion bonds have been produced between sheets of an Al-Li-Cu-Mg-Zr alloy using aluminium-4% copper vapour deposited metallic interlayers . Microstructural changes occurred both in the parent alloy and in the bond interface after diffusion bonding cycles and post-bonding heat t reatments were analysed. Different metallographic techniques (light mi croscopy, scanning and transmission electron microscopy) have been use d. Diffusion bonding trials were carried out using the same alloy (AA8 090), both in non-superplastic (T6) and superplastic conditions. Diffe rences in their behaviours in relation to diffusion bonding were obser ved.