Particle distribution and interfacial reaction of WC reinforced titanium matrix composites fabricated by wire and arc additive manufacturing

Abstract

In this study, preliminary experiments were conducted on wire and arc additive manufacturing (WAAW) with the injection of paraxial WC powder to achieve cost-effective fabrication of titanium matrix composites (TMCs) layers. The results indicated that injecting the powders from the rear of the molten pool did not influence the droplet transfer, and the WC particles exhibited a gradient distribution along the depth of the layer. A strong metallurgical bond formed between the particles and the matrix. The interfacial reaction during the process led to the formation of new phases, including W, W2C, TiC, and (W, Ti)C1-x solid solution. Continuous TiC layers or irregular mixed reaction layers were observed around WC particles. Furthermore, it was found that the W2C layer between WC and TiC may split into many smaller W2C grains.