Ti-6Al-4V Hybrid Structure Mechanical Properties – Wrought and Additive Manufactured Powder-Bed Material

Abstract

The implementation of additive manufacturing techniques in the production of mission critical structural components is challenged by its low throughput and limited build envelope. In recent years, hybrid production methods are emerging to bridge between the build volume and high throughput of conventional production methods and the design freedom enabled by additive manufacturing. The repeatability of material properties and the quality of the interface between the additive manufactured and wrought material are crucial for the adoption of hybrid manufacturing techniques by the industry. Here, the tensile behavior and fracture toughness of a hybrid Ti-6Al-4V alloy are examined in detail. Ti-6Al-4V pre-forms were built onto a wrought Ti-6Al-4V startplate and extracted via milling. Compact tension and uniaxial tension specimens extracted from the hybrid preforms demonstrated good fracture and properties with no preference for crack growth in neither the AM nor wrought materials. Microstructural characterization revealed a 40 mm transition layer into the wrought material which ends abruptly with no evidence of a gradually decaying heat-affected zone. The hybrid manufacturing approach studied here expands the current limitations of large-scale critical components with fine features and allow such structures to be produced with a higher throughput.