Selective laser melting of tungsten-copper functionally graded material

A tungsten-copper functionally graded material was processed based on SLM additive manufacture despite encountering some difficulties from materials characters. The effect of laser parameter on the interfacial defects and bonding performance are evaluated. The SLM produced tungsten is in columnar structures with random orientation. Plenty of fine tungsten grains are present at the bonding region, owing to a high cooling rate incited by the underlying copper. A metallurgically bonded interface with a 50-80 mu m inter-diffusion region is formed. The interfacial bonding mechanism, which associates with intense Marangoni convection at the interface, is revealed and discussed. (C) 2018 Elsevier B.V. All rights reserved.