Size and Orientation Dependent Thermal Strengthening of Ti/Ni Multilayer Thin Films
Junlan Wang (University of Washington), Zhou Yang (University of Washington)
Mechanics of Thin Films and Multilayered Structures
Tue 2:40 - 4:00
Salomon 203
Nanocrystalline metallic multilayer thin films are of great scientific significance due to their unusual structural, electrical, magnetic, optical and mechanical properties. The mechanical strength of metallic multilayer films can be affected by many factors, such as layer thickness, grain size and grain morphology, interface lattice mismatch, as well heat treatment. In this work, the size, orientation and temperature coupling in the strengthening mechanisms of titanium/nickel multilayer thin films is investigated. Ti/Ni multilayer thin films with various layer thickness is fabricated by magnetron sputtering under ultrahigh vacuum condition. The microstructural and mechanical properties are investigated by using x-ray diffraction, scanning electron microscopy and nanoindentation. The hardness of multilayer thin films is found to be strongly dependent on the individual layer thickness, loading orientation, polishing condition as well as the post-deposition annealing process. This talk will focus on the various aspects of the experimental study and the possible strengthening mechanisms due to this interesting size scale, loading orientation and annealing temperature coupling.