TITLE:
The Effects of Sintering Temperature on the Densification of Mechanically Alloyed W-Brass Composites
AUTHORS:
Baba Gowon, Kahtan S. Mohammed, Shamsul Baharin Bin Jamaluddin, Zuhailawati Hussain, Polycarp Evarastics
KEYWORDS:
W-Brass, Temperature, Densification, Prealloy, Hardness
JOURNAL NAME:
Open Journal of Metal,
Vol.5 No.3,
August
20,
2015
ABSTRACT: Prealloyed (PA) and premixed (PM) W-brass with the composition of 60 wt% W, 1 wt% Ni and 39
wt% brass was sintered at the temperature of 800°C, 920°C and 1000°C each. As a result of difficulties
in the densification of W-Cu and W-Cu alloys, mechanical alloying (MA) and activated sintering
were combined. The powders were mechanically alloyed for 13 hours to produce nanosized W
grains embedded in brass. The microstructure and properties of these composites with increase in
sintering temperature has been studied. Both prealloyed and premixed composites sintered at
800°C (solid state sintering) and 920°C (sub-solidus state sintering) have lower sintered densities
and hardness. The densification rate in the premixed composites was observed to be higher than
that of the prealloyed composites. Their densification and properties increased with the increase
in the sintering temperature. Premixed composite sintered at 1000°C had 91.0% sintered density,
180 Hv microhardness against 76.0% and 133 Hv respectively for prealloyed composite at the
same temperature. The values of electrical conductivity in both prealloyed and premixed composites
increased with increase in temperature.