Evidence of chemical short-range order in amorphous CuTi alloys produced by mechanical alloying

Abstract

Neutron and X-ray diffraction measurements have been made on series of eight mechanically alloyed CuTi amorphous alloys having atomic compositions between 75 and 30 at.% copper. The neutron measurements have shown that the alloys have a small impurity of hydrogen, which is attributed to contamination of the parent titanium powder. After appropriate corrections, the structure factors for these alloys have been found to be broadly similar to those of both glassy and molten CuTi specimens. The radial distribution functions provide some evidence of detailed differences between the atomic-scale structures of the molten, glassy and mechanically alloyed samples, which will need to be confirmed by measurements on samples of higher purity. The possible influence of gaseous impurities on the MA process is discussed.