Abstract
? 2022 Elsevier B.V.Thin Cu layers are inserted at the interfaces of initial Al/Ni binary multilayers during magnetron deposition to form the (Al/Cu/Ni/Cu)4 (ACNC) multilayers. The effects of thin Cu layers on interface structure, atomic diffusion, and phase transformation were studied. TEM results confirmed the asymmetric interface structure and distinct interdiffusion between Cu and Ni of the as-deposited ACNC multilayers. CuAl2 preferentially formed but totally disappeared at higher temperatures. The integrated and dense Ni/Cu/Al interfaces (Cu deposited on Al layer followed by an upper new Ni layer) in the middle and upper Al layers strongly hindered the diffusion at early stage, which suppressed the formation of Al3Ni in a large scale but did not change the phase composition at 773 K compared to the multilayers without Cu added. The findings suggested that the inserted Cu layer could avoid the energy reduction caused by intermixing of Al and Ni, but have less effect on the final products, which might help to realize the balance of storage stability and reaction performance with respect to the applications.
NSTL
Elsevier