Mutual dependency of mechanical properties and contiguity in W–Cu composites

The solid–solid and solid–liquid interfaces and their relationship to mechanical properties have been investigated in tungsten powder compacts infiltrated with copper. The application of Ni, Ni–Cu and Ni–Cu–P electroless coatings on primary W powders, prior to compaction was found to affect the contiguity and hence improve the yield and compressive strength of specimens.Scanning electron microscopy, X-ray diffraction analyses and mechanical properties were investigated with due allowance for the participation of contiguity in microstructure. Comparison of the observed data was made with those of conventional elementally mixed compacts.It was illustrated that the application of thin elemental or complex coating has a direct influence on the contiguity and mechanical properties. It was found that W powder coated with Ni–Cu–P coating exhibited the lowest contiguity, and highest relative density.