Fabrication, Microstructure and Stress Effects in Sputtered TiNi Thin Films

Sputtered thin films of equiatomic TiNi and TiNi(x) ternary alloys have excellent mechanical properties and exhibit robust shape-memory and transformational superelasticity. Furthermore, the energetic nature of the sputter deposition process allows the creation of highly refined microstructures that are difficult to achieve by melt-solidification. This paper presents recent work on the relationship between processing, microstructure, and properties of binary TiNi thin films, focusing primarily on residual stresses, kinetics of stress-relaxation and crystallization, and fine grain sizes achievable using hot-substrate direct crystallization. (Author)