SÍNTESE DO INTERMETÁLICO NiAl POR MOAGEM DE ALTA ENERGIA EM MOINHO ATTRITOR

Abstract

Ni and Al powders were mixed at Ni50Al50 composition (%at). These mixtures were processed by high-energy milling using Attritor and Spex mills at several milling times. In the Attritor mill, additional millings following a 2 3 factorial design were performed. Vial temperature during milling was measured. The milling products were characterized by X-ray diffraction (DRX) and scanning electron microscopy (SEM). Analysis of X-ray diffraction patterns, in addition to the evolution of vial temperature during milling, indicate NiAl intermetallic formation either in Spex or Attritor. However, in Spex this compound appears in lower milling times. The factorial design suggests that, when using an Attritor mill, lower ball-to-powder ratios promotes greater values of η. Observing SEM images, the Attritor samples show a flake-like morphology with finer particles as compared to those produced in the Spex mill.