EFFECTS OF MECHANICAL ALLOYING TIME AND ANNEALING TEMPERATURE ON THE PHYSICAL PROPERTIES OF Al – WC COMPOSITE POWDERS
In this study, mechanical alloying (MA) of Al-WC powder system was studied to produce aluminium composite powders having finer tungsten carbide fraction in aluminium matrix. For this purpose, elemental mixtures of 70 wt. % aluminium (Al) powder and 30 wt. % of tungsten carbide (WC) powder were mechanical alloyed for the duration of 2, 4 and 8 hrs. MA’ed powders then annealed at 300 ºC, 400ºC and 500ºC for 2 hours under inert atmosphere. Apparent densities of powders were measured in order to characterize both mechanical alloyed and annealed powders. Compressibility of the powders was determined by green density measurements after pressing.
Microstructural characterizations were conducted with X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Strain rates and crystallite sizes were measured according to fundamentals parameter approach (FPA) by applying Lorentzian function using software TOPAS 4.2.