The alloy formation of a Cu thin film with a i-AlPdMn 5f QC's after annealing to 350°C was analyzed. LEED and XPD both showed that the surface was oriented in a (110) orientation and was present in 5 domains, rotated by 72° to each other. It was noted that the layers stacked along the (110) direction have a stacking sequence and periodicity that resembles those of the d-AlMn QC phase along its 10f axis. It was found that the basic pentagons formed around the vacancy sites were aligned into pentagonal columns along the same direction. It was observed that in heated Al/Cu multilayer films in the presence of excess Cu, the formation of Al4Cu9 was favoured.