LAUSR

Abstract High-performance continuous SiC fiber reinforced titanium matrix composites (SiCf/Ti) are strongly required by aerospace vehicles, and their properties strongly depend on the microstructure of the interfacial reaction layer and the matrix. Thus, it is important to explore new routes to regulate these two SiCf/Ti components. In this work, α-phase-dominated and β-phase-dominated primary PVD Ti17 coatings were fabricated by controlling the bias voltage during physical vapor deposition (PVD). Their effects on the matrix microstructure evolution and interfacial reactions in SiCf/Ti after consolidation were further explored. It was found that compared with a primary α-Ti PVD Ti17 coating, a primary β-Ti PVD coating induced competitive growth between α-Ti and β-Ti grains in SiCf/Ti17 during consolidation. This yielded a smaller grain size and more β phase in the SiCf/Ti17 evolved from the primary β-Ti coating. In addition, a thicker reaction layer formed, as well as a lower interface strength and tensile strength in the SiCf/Ti17 evolved from a primary β-Ti coating, compared with the SiCf/Ti17 evolved from a primary α-Ti PVD Ti17 coating.