Fabrication and properties of the W-30wt%Cu gradient composite with W@WC core-shell structure

In the present work, a novel W-Cu gradient composite with W@WC core-shell structure has been fabricated successfully through vacuum pulse carburization and copper infiltration. The W@WC core-shell structure was introduced by vacuum pulse carburization of tungsten skeleton at 950 degrees C. Related microstructure and phase analysis revealed that the near surface region of the carburized tungsten skeleton was mainly covered by WC particles, the transition region with distributed WC particles, and the inner central region distant away from the surface without WC particles. The resulted W-Cu composite with W@WC core-shell structure after infiltration showed highly improved arc dispersion effect, smaller friction coefficient, more stable wear resistance and enhanced high-temperature compressive performances. In addition, the gradient structure also ensured the electrical conductivity of the W-Cu composite and maintained connected strength with CuCr alloy as an integral contact. (C) 2017 Elsevier B.V. All rights reserved.