Zr-based glass-forming film for fatigue-property improvements of 316L stainless steel: Annealing effects

With a 200-nm-thick Zr53Cu29Al12Ni6 glass-forming film, the four-point-bending fatigue life of a 316L stainless-steel substrate is improved from 4.4 × 105 cycles for the uncoated sample by ~ 10 times to 4.5 × 106 cycles at a stress level of 750 MPa. The fatigue life is further improved by more than 22 times to > 107 cycles when the film is annealed in the supercooled liquid region. The excellent mechanical properties of the thin film, specifically high strength and improved ductility, coupled with the good film adhesion to the substrate as well as the improved surface roughness, are the key factors that improve the fatigue resistance of the coated materials.