Structure of melt spun Ni₂₅Ti₅₀Cu₂₅ ribbons studied by X-ray diffraction

Abstract

Structure and transformation behaviour in NiTiCu melt spun ribbons has been investigated. The sbuctures of amorphous end heattreated ribbons were fitted using Rietveld refinement. After crystallisation, the following transformation sequence : B2->B19+B19' was found. The fractions of B19 and B19' phases in a mixture is equal 84 wt% 16 wt%, respectively. Quenching and annealing causes shifts in characteristic temperatures. The precipitation process is mainly responsible for the changes in the transformation course.