MATERIALS PROCESSING I: SYNTHESIS OF MmNi5 BY COMBINED MECHANICAL ALLOYING -LOW TEMPERATURE HEATING PROCESS

M. R. ESQUIVEL; J. ANDRADE GAMBOA; F. C. GENNARI; G. O. MEYER

ADVANCED PROCESSING OF METALS AND MATERIALS: NEW, IMPROVED AND EXISTING TECHNOLOGIES

TMS The Minerals, metal and materials Society

Año: 2006; p. 517 - 526

A MmNi5 alloy is synthesized by a combination of mechanical milling and low temperature heating processes. Synthesis time is 40 h for powders milled in a low energy ball mill at room temperature. A reduction in milling time is obtained if massive sample is mechanically milled at shorter times (2 h to 10 h) and heated at temperatures lower (600 ºC) than the usual temperatures used in equilibrium methods (>800 ºC). The alloy formation is detected even at a combination of temperatures as low as 200 ºC and milling times as short as 5 h. The temporal evolution of mechanical milling process was followed by both X-ray diffraction (XRD) and scanning electron microscopy (SEM) to detect the main stages of milling. Four stages were detected: Initial, Intermediate, Final and Completion. These stages were correlated to an enhancement of the synthesis method by  combination of times of milling shorter than 10 h and temperatures of heating lower than 600 ºC.