The Effects of Carbides on the Mechanical Properties of Tantalum

Carbon additions increase the strength of tantalum as do oxygen and nitrogen additions. However, the effectiveness of carbon as a strengthener does not diminish as rapidly with increasing temperature up to at least 2,700°F as does the effectiveness of oxygen or nitrogen. This is because carbon reacts with tantalum to form finely dispersed carbides even in the absence of zirconium. Carbide dispersions can be used as an auxiliary strengthener of solid-solution-strengthened tantalum-base alloys. At very high temperatures (above about 3,000°F) the carbon solubility in tantalum increases rapidly with temperature, and even the reactive metal carbides dissolve in tantalum. and lose their effectiveness.