Improving fracture toughness of B4C – SiC composites by TiB2 addition

Abstract

B4C-SiC composites can be used in many areas due to their superior properties. However, in order to be used as a body armor material in areas requiring high performance, their fracture toughness needs a degree of improvement. In this study, 0–20 wt% TiB2 was added to B4C-SiC samples that were consolidated at 1950 °C by spark plasma sintering method. The contribution of TiB2 to the microstructure, elastic and mechanical properties of B4C-SiC composites were investigated. The highest hardness was measured to be 29.5 GPa with 15 wt%TiB2 addition. The highest fracture toughness was 3.08 MPa.m1/2 found at sample made with 10 wt% TiB2. Addition of 10 wt% TiB2 increased the fracture toughness by 28%, with only a 5% decrease in relative density. In addition, the fracture mode of B4C-SiC-TiB2 composites is intergranular due to the addition of TiB2.