To use chromium thin films to improve properties of
zirconium alloy, some effects of composite films of niobium layer and
chromium layer have been studied. The interface was studied with scanning electron microscope (SEM), the grain morphology of chromium film surfaces were observed with atomic force microscope (AFM), scratch adhesion tests were performed on a WS-97 Automatic Scratch Tester to examine the adhesion of films to its substrate. The results showed that interface of films/substrates is well-knit, so do the interfaces of niobium layer and chromium layer. No compound or interphase was found, though there are visible boundary. The grains of 2 靘 thickness chromium films behave the compact fine fibre grains with vaulted top and the grains sizes is less than microns. When the thickness of films layer is 2 靘, it is found out that the adhesion of the film (1 靘 Nb+1 靘 Cr+Zr substrates) is 2.35 times that of the film?(1 靘 Cr +1 靘 Nb +Zr substrates) and 3.0 times the film?(2 靘 Cr +Zr substrates), for the reason is the changes of structure and performance , order of layers and better toughness of niobium抯. Therefore, a niobium layer deposited on the chromium films outside is better way to improve films performance rather than add of the thickness of chromium films.