Fracture Toughness of Tungsten Carbide Reinforced Fe-Matrix Surface Composites

• Published in: Materials science forum Vol. 898; pp. 1453 - 1458
• Main Authors: Zhang, Xi, Wang, Xin, Wu, Hong, Zhong, Li Sheng, Xu, Yun Hua, Fu, Yong Hong
• Format: Journal Article
• Language: English
• Published: Pfaffikon Trans Tech Publications Ltd 01.06.2017
• Subjects: Alloys; Argon; Bonding strength; Cast iron; Crack propagation; Cracks; Diamond pyramid hardness tests; Fractography; Fracture mechanics; Fracture toughness; Graphite; Heat treatment; Indentation; Loads (forces); Particulate composites; Scanning electron microscopy; Tungsten carbide; X-ray diffraction; Fracture Toughness; Tungsten Carbide; Iron Matrix Surface Composites; In Situ; Indentation
• DOI: 10.4028/www.scientific.net/MSF.898.1453
• ISSN: 0255-5476; 1662-9752

Tungsten carbide (WC) reinforced Fe-matrix surface composites were prepared by in-situ synthesis between tungsten plate and graphite in grey cast iron. The microstructure, fracture toughness, and fracture of the WC layer were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and the Vickers indentation technique, respectively. The results revealed that heat treated at 1125°C for 135min in argon atmosphere the main phase was WC with a bit of α-Fe. The fracture toughness (KIC) of the WC layer calculated using the Niihara’s equation, was 5.21 MPa·m1/2. Fractographic observations revealed that cracks propagated along the grain boundary under 2 kg loads. Moreover, both the WC particles and the interface between the WC layer and the matrix had a strong bonding strength.