Investigation on the microstructure and properties of W-10 wt% Cu prepared by sintering and infiltration

In the present study, Three tungsten powder mixtures with average particle size of 6 mu m containing 0.05, 0.25 and 0.05 wt% of activators (Ni and Co) were used to fabricate W-10 wt% Cu composites by sintering and infiltration method. The mechanically mixed powder mixtures were compressed under CIP to prepare green compacts of cylindrical shape. Then, green compacts were sintered at 1350-1600 degrees C for 4 h and then infiltrated/ penetrated by liquid copper under the hydrogen atmosphere in order to obtain W-10 wt% Cu composites. The sintered samples as well as its infiltrated compacts were characterized by scanning electron microscopy (SEM), EDS and XRD methods. Investigation the physical and mechanical properties carried out by density and electrical resistivity measurement and also tensile test. The obtained results exhibited that Ni doped samples achieved to density of 15.05-15.70 g/cm(3) at lower sintering temperature rather than Co containing specimens. Also, it was found that activating capability of additives depend on its concentration as well as sintering temperature. The microstructural observations revealed mutual dependency of mechanical properties of composite and W-W contiguity. Maximum tensile strength for Ni and Co containing composite was measured about 650 and 619 MPa, respectively.