Effect of boron doping on fracture behavior of carbon fiber reinforced lithium aluminosilicate glass ceramics matrix composites

Boron doped carbon fibers reinforced lithium aluminosilicate matrix composites (C-f/LAS) were prepared by slurry infiltration combining with hot pressing procedure. The doping of boron significantly enhances the fracture toughness and fracture work of the C-f/LAS composites, which could reach the highest fracture toughness of 25.0 +/- 0.4 MPa m(1/2) and the work of fracture of 24.5 +/- 2.8 kJ/m(2), respectively. The work of fracture of boron doped C-f/LAS composites is 2.2 times of that of the boron free C-f/LAS composites. The fracture mode of C-f/LAS composites changed from ductile fracture to brittleness fracture with increasing the boron content from 0 to 4 wt%. The connection of the fracture behavior and the interfacial microstructure was examined to establish a direct relationship among interfacial microstructure, interfacial chemistry and fracture behavior of the studied composites. (C) 2016 Elsevier Ltd. All rights reserved.