Hot Corrosion and Oxidation Behavior of Network Structured TiB_w/TA15 Composite at 1073 K

The hot corrosion and high temperature oxidation performance of the TiB_w/TA15 composite were tested at 1073 K for up to 100 h. The final mass gain caused by the high temperature oxidation was only 16.9% of that caused by the hot corrosion, showing that the effect of hot corrosion is much larger than that of oxidation. After 100 h of high temperature oxidation testing, an approximately 50 μm-thick oxide scale formed on the substrate surface, consisting of mixed TiO₂ and Al₂O₃ oxide. An approximately about 300 μm-thick hot corrosion scale, mainly composed of TiO₂ and Al₂O₃ with holes and cracks, was generated after 100 h of hot corrosion testing. The change of acidity/basicity in the molten salt caused by the self-circulating sulfurization/chlorination–oxidation cycle and basic dissolution was the mean reasons for hot corrosion.