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Shape memory alloy TiNi films were prepared on Si and Si/SiO2 by co-sputtering of TiNi target (Ti 50 at.% and Ni 50 at.%) and Ti target (99.999 at.%). When comparing Si/TiNi with Si/SiO2/TiNi, the addition of SiO2 sandwich layer did not result in significant change in the crystalline structures and shape memory properties. The SiO2 sandwich layer served as an effective diffusion barrier in preventing formation of interfacial titanium silicide at the expense of film adhesion. As revealed by X-ray photoelectron spectroscopy, under the same conditions, the interfacial diffusion zone in Si/TiNi system was approximately 120 nm while in Si/SiO2/TiNi system the diffusion zone was only approximately 30 nm—a four-fold reduction in inter diffusion. Meanwhile, the scratch adhesion testing registered a sharp drop in adhesion of the film from 170 mN in Si/TiNi system to 60 mN in Si/SiO2/TiNi system. [Copyright &y& Elsevier]

Nanocrystalline TiN has been imbedded in amorphous silicon nitride matrix to form a super hard nanocomposite thin film (nc-TiN/a-SiNx) via magnetron sputtering. Adjusting Ti and Si3N4 target power ratio altered film composition, size, amount and distribution of the nc-TiN phase. At a Ti target power density of 5.5 W cm−2, the Ti to Si3N4 target power ratio should be greater than unity in order for nc-TiN to form, otherwise, Ti will dissolve in amorphous SiNx. The relationship between the film hardness and the crystallite size show Hall–Petch and anti-Hall–Petch relationship. A ‘scratch crack propagation resistance’ parameter, or CPRs=Lc1(Lc2−Lc1), has been proposed to approximate thin film toughness from the critical load data easily obtained from a scratch adhesion test. [Copyright &y& Elsevier]

Abstract: Excellent thermal shock resistance is required for thermal protection coatings experiencing high/low temperature cycles. In this paper, the pure ceria oxide coatings were deposited by electron beam physical vapor technique at different power densities. The grain orientation, morphology, hardness and thermal cycling oxidation behavior of CeO2 coatings were systematically studied. The deposition power density has remarkable influence on the preferred crystal orientation and morphology of the coatings. The heating–cooling test cycles from 1000°C to room temperature indicate that the CeO2 coatings with the columnar structure show excellent thermal shock resistance. The hardness of the CeO2 coating varies with thermal cycling. [Copyright &y& Elsevier]