Micro-structure, mechanical properties and comparison of monolithic and laminated Ti-B₄C composite with Al doped

Compared with homogenous monolithic structure, laminated structure was utilized to improve the fracture toughness of Ti/B₄C composite in this work. Monolithic and laminated composite with Al doped as sintering aids were successfully prepared via vacuum hot-pressing sintering. Structurally, laminated composite was designed to stack periodically with Ti(Al) and B₄C layers. The results of XRD and EDS suggested that laminated structure restrained the interfacial reaction between Ti and B₄C phase by confining the contacting area between Ti and B₄C layers on interface. As expected, the fracture toughness of the laminated composite reaches to 9.22 ± 1.12 MPa m^1/2, which increased by approximately 201% compared with monolithic composite (4.58 ± 0.81 MPa m^1/2). This remarkable improvement of fracture toughness was attributed to multiple-layers structure, ductile Ti layers and crack deflection. Thus, laminated structure is a promising approach to produce high toughens metal/ceramic composites.