S. Ingole, H. Liang, Texas A&M University, College Station, TX; P. Mohanty, The University of Michigan, Dearborn, MI

Summary: NiTi coatings are attractive due to their unique shape memory effect as well as wide applications in engineering and biological applications. The present investigation enunciates the friction and wear behavior of thermally sprayed NiTi coatings as well as their bulk alloys. The tests were conducted using reciprocating pin-on-disc configuration against bearing balls. Due to the surface roughness, initial break-in period behave quite differently for the coatings and the bulk alloy. After deforming asperities, the coating materials showed a stable friction. The coefficient of friction for NiTi coatings was found to be (m = 0.77 Std. Dev = 0.1) higher compared to the coefficient of friction for bulk NiTi alloys (m = 0.67 Std. Dev 0.11). The wear mechanisms of these coatings and bulk alloy were studied at nanometer length scale as well as micrometer level using an atomic force microscope (AFM).