Microstructure and mechanical properties of continuous carbon fiber-reinforced ZrB2-based composites via combined electrophoretic deposition and sintering

A process combining electrophoretic deposition (EPD) with hot pressing (HP) was developed to fabricate continuous carbon fiber-reinforced ZrB 2 -based composites (C f /ZrB 2 -based composites). ZrB 2 -based ultra-high temperature ceramic (UHTC) particles were uniformly pre-coated on continuous carbon fibers via EPD. Then, the UHTC-coated carbon fibers were stacked and hot pressed to prepare the C f /ZrB 2 -based composites. Microstructure observations revealed that almost no micro-pores were found in the inter-bundle and intra-bundle regions of fibers after HP. The flexural strength , fracture toughness and the work of fracture of the C f /ZrB 2 -based composite were measured as 199 ± 26 MPa, 6.71 ± 1.29 MPa·m 1/2 , and 754 ± 58 J/m 2 , respectively. Based on the observations of non-brittle fracture behavior , fractured morphology and crack propagation , the enhanced fracture properties were mainly attributed to the multiple toughening mechanisms, such as fiber pull-out, fiber bridging, crack deflection and branching along the interfaces.