SPUTTER-DEPOSITION TECHNIQUE, TRANSFORMATION INTERVALS AND MECHANICAL PROPERTIES OF TI-NI-HF AND TI-NI-PD HIGH TEMPERATURE SHAPE MEMORY ALLOYS THIN FILMS

摘要

A sputter deposition technique of TiNiHf and TiNiPd high temperature shape memory thin films in a production PE 4450 sputtering system has been developed. The technique implies simultaneous sputtering from three individually powered targets (TiNi direct current (DC) target, Hf/Pd DC target and Ti/Ni DC/radio frequency (RF) target) onto a rotating pallet. The power settings for each of three targets in a given deposition ran were calculated from the atomic composition of the film to be deposited and experimentally obtained relations "applied power" versus "deposition rate" for a corresponding target. The actual film composition measured by Energy Dispersive X-Ray Spec-trometry (EDXS) and Wavelength Dispersive X-Ray Spectrometry (WDS) was found to be in a good agreement with calculated numbers. Transformation intervals and mechanical properties of the deposited films have been measured after the crystallization anneal. The loading/unloading stress-strain curves in tension were recorded, shape recovery measured and shape memory alloy(SMA)-actuated devices for the selected film compositions built.