Microstructure, hardness and mechanical properties of two different unalloyed tantalum wires deposited via Wire + Arc Additive Manufacture

TL;DR

This study demonstrates that Wire + Arc Additive Manufacturing can produce large, high-quality tantalum parts with superior mechanical properties and reduced costs, using different wire chemistries.

Contribution

It introduces a novel application of Wire + Arc Additive Manufacturing for large-scale tantalum components, analyzing effects of wire chemistry on properties.

Findings

High mechanical strength and ductility of deposits

Yield strength exceeds commercial tantalum

Potential for low-cost, rapid manufacturing of tantalum parts

Abstract

An innovative way of producing large-scale unalloyed tantalum parts, based on the Wire + Arc Additive Manufacturing process, has been developed in this study. Two different unalloyed tantalum wires have been used to deposit 200-mm-long structures in tantalum. The effect of the wire chemistry on microstructure, hardness, porosity, mechanical properties and strain localisation has been investigated. The deposits showed high integrity and excellent mechanical properties, with yield strength, ultimate tensile strength and elongation as high as 234 MPa, 261 MPa, and 36 %, respectively. Indeed, yield strength was higher than commercially available tantalum, even though, in this study, the grains were large and had a high aspect ratio. Wire + Arc Additive Manufacture has clearly shown the potential to produce tantalum components with relatively low cost and reduced lead time, thus offering a new robust and viable manufacturing route.