Microstructure and mechanical properties of Si and YN doped powder metallurgical tantalum

Tantalum has a wide range of applications due to its high melting temperature, its corrosion resistance and its mechanical and electrical properties. One of these applications are fine wires which are needed for Ta-capacitors. During fabrication of such components, the wires are exposed to high temperatures and, thus, grain growth combined with embrittlement becomes a major problem. In the present work, the effects of doping with small amounts of Si and YN on microstructure and mechanical properties of annealed Ta-wires have been investigated. Doped samples show a higher hardness and strength than samples of pure powder metallurgical (PM) Ta; however, the grain growth kinetics are very similar. Samples doped with Si and samples doped with both Si and YN exhibit almost identical properties.