Compositionally graded Ti6A14V+TiC made by direct laser fabrication using powder and wire

Ti6A14V reinforced with TiC has been fabricated as compositionally graded material by direct laser fabrication using TiC powder and Ti6A14V wire which were fed simultaneously into the laser focal point. The microstructure along the length of the sample has been characterised using X-ray diffraction and scanning electron microscopy. The results show that the composition along the length changes as expected from the imposed changes in feed rate when allowance is made for the different capture efficiency for the powder and the wire. Some unmelted TiC has been observed in regions where the TiC fraction was high, but along most of the length of the samples TiC was completely melted and formed primary TiC, eutectic TiC and secondary TiC. Some preliminary tribological properties of the compositionally graded material were obtained using a sliding wear test which showed that the tribological properties of Ti6A14V are improved by the reinforced TiC particles with the optimum frictional behaviour being found with approximately 24 vol% of TiC. (c) 2006 Elsevier Ltd. All rights reserved.