Study of structure and usage of mechanically alloyed nanocrystalline Ti–Cu–Zn powders in powder metallurgy

Abstract

Nickel silver alloys are popular for their silver colour and corrosion resistance. These alloys are traditionally solid solutions of Cu, Ni and Zn. Substitution of Ti, which is a biocompatible metal, for Ni in those alloys, can improve its various utilisations, so the aim of this research work was to study the structure and usage of mechanically alloyed nanocrystalline Ti–Cu–Zn powders in powder metallurgy. The Ti content in alloyed powder with a silver contrast was also minimised. The products were characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM) examinations. Ni in the nickel silver alloys (22%Ni) could be substituted by Ti and the same silver colour could be obtained with 10%Ti in the alloy. Alloyed powder with a silver contrast and –10 nm grain size could be obtained by the optimisation of milling parameters. After 5 h of the powder milling, in addition to Cu–Ti solid solution, TiCu₄ was also formed. It was also shown that by increasing the milling time amorphous alloys could be obtained. After sintering the powder, in addition to Cu–Ti solid solution, TiCu₄, TiCu₃, TiCu₂, TiCu could be formed.