Interface characterization of duplex metal-coated SiC fiber-reinforced Ti-15-3 matrix composites

Abstract

The interfacial reaction behavior of duplex metal (Cu/Mo and Cu/W)-coated SiC (SCS-6) fiberreinforced Ti-15-3 composites, before and after thermal exposure, has been studied. The effect of thermal exposure on the shear sliding resistance of these composites was also obtained using a thinspecimen push-out test. The results are compared to those of an original SiC (SCS-6) fiber-reinforced Ti-15-3 composite. The interfacial reaction behavior is strongly affected by the existence of a coating layer. Both the Cu/Mo and Cu/W coating layers prevent the growth of a reaction layer. However, the coatings could not effectively prevent diffusion of alloying elements; only the W layer exists after the thermal exposure. On the other hand, the interface shear sliding stress minimally depends on the duplex metal coating layers prior to the thermal exposure, and this sliding stress in both the SiC/Cu/Mo/Ti-15-3 and SiC/Cu/W/Ti-15-3 composites decreases slightly relative to that in the SiC/Ti-15-3 composite. After thermal exposure, the interface shear sliding stress increases for the SiC/Ti-15-3 composite. In distinction, the interface shear sliding stress significantly decreases after thermal exposure in both the SiC/Cu/Mo/Ti-15-3 and SiC/Cu/W/Ti-15-3 composites. Theses behaviors are attributed to the decrease of radial clamping stress, which originates from a volume expansion associated with the ␤ → ␣ phase transformation.

SiC–Ti layered material prepared by binder-treated powder sintering

“…Interface is one of most important issues in many of these applications, i.e., semiconductor physics and electronic device. Moreover, the performance of the composite is controlled to a large extent by the stability of the interface at high temperatures (Guo et al, 1999). Interface reactions between the matrix and the reinforcing materials may lead to structural instability and thereby deteriorate the mechanical properties of the composite.…”

Formation of interfacial microstructures of Mo‐coating modified SiCf/Mo/Ti‐6Al‐4V composites

“…Her et al also pointed out that the fracture property is lower on account of higher interfacial crack density and higher interfacial bonding strength in the SCS‐6/Ti‐25‐10 composite modified with Ag/Ta duplex coating. The remarkable effect of Cu/Mo and Cu/W duplex coatings on the interfacial reaction and interfacial shear stress in SCS‐6/Ti‐15‐3 composite was reported by Guo et al Meanwhile, their study illustrated that Cu/Mo and Cu/W duplex coating can excellently improve the fracture resistance, avoid interfacial debonding, and maintain the fiber strength. Notably, the Cu/Mo duplex coating can increase the axial tensile property and fatigue resistance.…”