M. Ahangarkani, K. Zangeneh-Madar, H. Abbaszadeh, A. A. Rahmani , S. Borgi,
Volume 11, Issue 3 (september 2014)
Abstract
In the present paper, the influence of cobalt additive on the sintering/infiltration behavior of W-Cu composite
was studied. For this purpose, the mixed powders of tungsten and cobalt were compacted by CIP method and then
sintered at 1450, 1550 and 1600 °C in a hydrogen atmosphere. The sintered specimens at 1550 °C were subsequently
infiltrated with liquid copper at 1250 °C for 10, 60 and 120 min. The microstructure and composition of samples were
evaluated using SEM, EDS as well as XRD techniques. The density of the sintered samples was measured by
Archimedes method. Vickers indentation test was used to measurement hardness. It was found that sintering
mechanism of tungsten powder depends on temperature and cobalt additive content. Also, the best infiltration behavior
was observed in the samples with optimum cobalt value. In addition, it was found that the W-W contiguity as well as
dihedral angle decreases as cobalt increases. Density and hardness of infiltrated specimens are attained 16.28-16.79
g.cm-3 and 220-251 VHN, respectively.
S. Borji, K. Zangeneh-Madar, M. Ahangarkani, Z. Valefi,
Volume 14, Issue 1 (March 2017)
Abstract
In this paper the feasibility of fabricating controlled porous skeleton of pure tungsten at low temperature by addition of submicron particles to tungsten powder (surface activated sintering) has been studied and the best parameters for subsequent infiltration of Cu were acquired. The effects of addition of submicron particles and sintering temperature on porous as well as infiltrated samples were studied. The samples were examined by scanning electron microscopy (SEM), Vickers hardness measurements and tensile test. The composites made have been investigated and revealed the making W-Cu composite with good density, penetrability, hardness and microstructure. Consequently, the sintering temperature was reduced considerably (Ts≤1650oC) and a homogeneous porous tungsten was obtained. Also, composite prepared by this method exhibited elongation about 28% that is much more than conventional W-15%wt Cu composites. This method of production for W–Cu composites has not been reported elsewhere
