Mechanické vlastnosti slitin NiTi pro biomedicínské aplikace

Abstract

The diploma thesis is concerned with research into mechanical properties of NiTi alloy for biomedicine application that underwent different heat treatment. The alloy with chemical composition Ni51,25Ti48,75 (at. %) was in form of sheets with the thickness 2,0 mm and 3,5 mm. The research of microstructure was conducted on specimens as received, aged, solution treated, and solution treated and aged. Metallographic research was executed via an optical and a scanning electron microscope. The microstructure was comprised of martensitic and austenitic phase at the same time. As received, aged, and solution treated and aged specimens were tested via tensile test to the fracture and three-point flexural test. Microhardness test was conducted on all specimens. Fractography analysis of ruptured specimens was performed via the scanning electron microscopy. The effect of microstructure on mechanical and fracture properties is summarized in the conclusion. Superelastic effect was observed at aged, and solution treated and aged specimens, but the solution treated and aged specimens evinced brittle behaviour.