In this work, tungsten carbide particles (WCp, spherical and irregular particles)-reinforced iron matrix composites were manufactured utilizing a liquid sintering technique. The mechanical properties and the fracture mechanism of WCp/iron matrix composites were investigated theoretically and experimentally. The crack schematic diagram and fracture simulation diagram of WCp/iron matrix composites were summarized, indicating that the micro-crack was initiated both from the interface for spherical and irregular WCp/iron matrix composites. However, irregular WCp had a tendency to form spherical WCp. The micro-cracks then expanded to a wide macro-crack at the interface, leading to a final failure of the composites. In comparison with the spherical WCp, the irregular WCp were prone to break due to the stress concentration resulting in being prone to generating brittle cracking. The study on the fracture mechanisms of WCp/iron matrix composites might provide a theoretical guidance for the design and engineering application of particle reinforced composites.
Keywords: fracture mechanism; mechanical properties; microstructure; particle reinforced composites; second phases; tungsten carbide.