2004 Volume 45 Issue 12 Pages 3241-3246
Isothermal oxidation behavior of in situ synthesized TiB/Ti composites has been investigated. Samples of titanium matrix composites reinforced with 0, 5 and 8 vol% TiB particulates were oxidized at 823, 873, and 923 K for 300 h in atmospheric air. Scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry, and transmission electron microscopy (TEM) were used to identify oxidation products and characterize oxide scale morphology. Oxidation was observed to follow parabolic kinetics. Rate of oxidation decreased with the increase of TiB reinforcements. The oxide scale formed on TiB/Ti composites was rutile-type TiO2. No other oxides were observed within the oxide scale. The increased oxidation resistance due to the addition of the in situ synthesized TiB reinforcement was attributed to the improved tendency for the formation of thin and dense oxide avoiding crack and spallation, the strong enough interfacial cohesion and the clean interfacial microstructure between the reinforcements and the titanium matrix alloy.