A STUDY OF AMORPHOUS FE58TA42 ALLOYS PRODUCED BY MECHANICAL ALLOYING

The solid state 'amorphisation' reaction in Fe58Ta42 samples produced by mechanical alloying (MA) has been studied using X-ray and neutron d iffraction; neutron small-angle-scattering (SAS) and Mossbauer spectro scopy. The diffraction and Mossbauer measurements have shown that the reaction is rapid and that the parental elements are transformed into a genuinely amorphous alloy after 6 h of MA in a conventional Spex 800 0 mill. The total structure factor S(Q) of the amorphous alloy has bee n obtained and the reduced radial distribution G(r) derived from its F ourier transform. In addition, the neutron SAS has been used to study the changes in the large scale structures of the samples in the initia l stages of the reaction, which were measured in the as-received and c ontrast-matched states. The results are consistent with the presence o f a duplex, filamentary, composite whose interfaces are fractal, in th ose samples with the shortest times of MA. (C) 1997 Elsevier Science S .A.