Effects of heat treatment on interfacial characteristics and mechanical properties of titanium matrix composites reinforced with discontinuous carbon fibers

Weak interfacial bonding was a significant problem in titanium matrix composites (TMCs) reinforced with carbon fibers (CFs). In this study, heat treatment (HT) up to 1000 degrees C was applied on powder metallurgy Ti-6Al-4V matrix composites reinforced with discontinuous CFs to obtain different interfacial structures. Mechanical tests at both room-temperature and 500 degrees C showed that the best mechanical properties were attained at HT temperature of 900 degrees C. To understand the underlying mechanism, the phase structure, grain morphology and interfacial microstructure were examined. It was found that as HT temperature was in-creased, the interface thickness increases continuously and obvious grain growth happens at 1000 degrees C. Suitable interfacial reaction and fine grain size are identified as critical structural parameters to obtain high -performance CFs/TMCs. This study may provide new insight into the role of interfacial structure played in the strengthening effect of CFs/TMCs. (c) 2021 Elsevier B.V. All rights reserved.