Influence of feedpowder morphology on microstructure and mechanical properties of Tantalum produced by cold spray additive manufacturing

Abstract

In this study, two types of tantalum powders were deposited using cold spray additive manufacturing (CSAM). We focused on comparing the effects of hydride-dehydride polygonal tantalum powder (A-Ta) and plasma-atomized spherical tantalum powder (STa) on the microstructure, mechanical properties, and tribological performance of the resulting deposits. Results revealed that under identical spraying conditions, A-Ta powder achieved a higher deposition efficiency (DE) of 86 %, compared to 61 % for STa powder. Both deposits demonstrated low porosity; however, the A-Ta deposit exhibited significantly superior mechanical properties, with a tensile strength of 350 MPa, approximately 2.1 times higher than the STa deposit. Moreover, the A-Ta deposit showed enhanced wear resistance. At a heat flux density of 2.4 MW/m², the A-Ta deposit demonstrated excellent ablation resistance, exhibiting a linear ablation rate of only −0.0012 μm/s after a 10-s exposure. These findings highlight the considerable potential of low-cost polygonal A-Ta powder for high-temperature ablation protection applications, establishing it as a promising candidate for CSAM of tantalum layers.