Microstructure and Abrasive Wear Properties of WC/Fe Matrix Composites Under Different Preform Wall Thicknesses

In this paper, preforms with three-dimensional structures and different thicknesses were constructed by 3D printing technology, and WC particle reinforced high-chromium cast iron (HCCI) composites was prepared by infiltration casting method. The microstructure of the WC/Fe matrix composites was investigated using scanning electron microscopy (SEM), energy spectroscopy (EDS), X-ray diffraction (XRD) and electron backscattered diffraction (EBSD). The effects of different preform wall thickness on the hardness and three-body abrasive wear properties of the composites were tested. The results showed that with the increase in the wall thickness of the three-dimensional preform from 2.5 to 10 mm, the volume of the composite zone formed by the dissolution diffusion reaction of WC and HCCI gradually increased from 31.8 to 41.2%. The microstructure was composed of composite zone, matrix and WC particles partially dissolved. The hardness of the composite zone increased at first and then decreased, while the wear weight loss of the composite showed an opposite trend. Compared with the wall thickness of 2.5 mm, the minimum wear weight loss of the composite was 0.2821 g for a wall thickness of 7.5 mm, and the wear resistance was improved by 12.8%. The hardness and wear resistance of WC/Fe matrix composites at different wall thicknesses were mainly related to the diffusion of the preform and the formation of the composite zone.