TiNi thin films prepared by cathodic are plasma ion plating

The TiNi intermetallic compound possesses shape memory effect and pseudoela sticity. The demand for integration and the high price of TiNi alloys neces sitate their application as a surface layer upon base materials. In this st udy, an attempt was made to obtain high quality TiNi film using the CAP pro cess. Substrate bias voltage, working pressure and target composition were changed to understand the relationship between the coating parameters and f ilm microstructure. The microstructures of the deposited films were charact erized using XRD and TEM. SEM was used to observe the surface and cross sec tional morphology of the films. EDS was used to analyze the composition of the films. DSC was used to understand the thermal behavior of the deposited films. The experimental results show that TiNi films can be prepared using a CAP process. When the negative bias voltage is high enough, crystalline TiNi film can be deposited using CAP without heat treatment. Phases existin g in the deposited film depend strongly on the target composition and the c rystallinity of the deposited film depends strongly on the substrate bias v oltage. After 450 degrees C heat treatment for 4 h, the martensitic transfo rmation temperature of all of the corresponding films was increased to room temperature due to thermal healing of defects. (C) 2000 Elsevier Science S .A. All rights reserved.