A structure formation in Ti-Ni powder after high-energy mechanical treatment

Abstract

Abstract In this work a structure formation in Ti-Ni powder after high-energy mechanical treatment in a planetary ball mill with an acceleration of 60g are presented. Mechanical treatment time of powder was 5-300 seconds. It was shown the powder in initial state consists of phase mixture TiN (B2, B19`), Ti2Ni (E93) and TiNi3 (D024). The lattice parameters of powders not significantly change at mechanical treatment and correspond in good agreement with literature data. The quasi-amorphous phase is formed after mechanical treatment and the relative content of phases change so that the relative content of quasi-amorphous phase increases steeply from 0 % to 45 % in first 10 second of treatment mechanical treatment and not significantly changes at more prolong milling. The full widths at half maximum of peaks not significantly change to 10 second mechanical treatment, but the more prolong milling leads to them increasing due to forming of dislocation in all phases, wherein the value of the dislocation density of Ti2Ni phase is more than of TiNi and Ni3Ti phases and corresponds to 1013 cm−2 at 60 second of mechanical treatment.