Novel Morphology for NiWMo Carbides Obtained by Mechanical Alloying and Quenching

Abstract

In the present work, the synthesis and decomposition of low-dimensional materials from a Ni15Mo25W10C50 system produced by mechanical alloying was reported. During the milling process, the resultant phases were WMoC and NiC, and after sintering and quenching, MoNi3, WMo, Ni4W, WC, MoNi and Mo2C were found. The samples were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Nanotubes with the lengths ranging from 500 nm to 2 μm, spheres and novelty globular particles with sizes ranging from 40 to 600 nm as well as “petal-like” estructure were observed. The results revealed the formation of a microstructure with morphology similar to spinodal decomposition followed by a sequence of invariant reactions leading the production of modulated and novel branched structures. We proposes a theoretical mechanism of formation that is associated with the modulated structure observed after quenching.