Oxidation Behavior of TiB2/Ta-W Composites

TiB2/Ta-W composites and Ta-10W alloy are prepared by hot-press sintering. The composites and alloy are oxidized in air at 700°C, 800°C and 900°C, respectively. The phase components of the as-prepared composites, alloy and oxidized layer were analyzed through XRD and SEM/EDS. The results showed that TiB2 reacted with both tantalum and tantalum oxide on the surface of Ta particles, which leads to the formation of intermetallic compounds Ta2B and Ta3B2. An oxidation layer of Ta2O5 solid solution was identified. Oxidation kinetics curves of all samples in air obeyed liner law, because a stable protective oxide scale could not be formed on the surface of samples.