Microstructural study on the effect of directional infiltration and Ni activator on tensile strength and conductivity of W-10 wt%Cu composite

It is tried in this research to investigate the effect of uni-directional infiltration of copper as well as Ni activator on the tensile behavior and thermal conductivity of infiltrated tungsten skeleton. For this purpose, three different kinds of W-10 wt%Cu composites were fabricated based on liquid copper infiltration into porous tungsten skeleton. For studying the effect of Ni activator, one of the samples was prepared by solid activated sintering. To investigate the directional infiltration, an interesting method was designed to overcome the wall tension problem. In this method, the lateral surfaces of sintered skeleton were covered by a sprayed layer of zirconia. Chemical analysis of the material after erosion test was obtained using EDS analysis. SEM images were employed to identify the microstructure evolution due to erosion. The obtained results exhibited that sample prepared with zirconia cover has higher tensile strength and conductivity as well as better homogeneity in microstructure and properties. These results were discussed based on microstructural evolution, remained porosities. This study provides an insight into the importance of uni-directional infiltration of refractory porous skeletons by low melting metals.