Microstructure and abrasive wear characteristics of in-situ WC bundles - reinforced iron matrix composites

An in-situ synthesis process combining an infiltration casting with a subsequent heat treatment was applied to fabricate special tungsten carbide (WC) bundles-reinforced iron matrix composites in this work. The microstructure and wear-resistance of the tungsten carbide bundles reinforced iron matrix composites were studied by using scanning electron microscopy, X-ray diffraction and wear tester. Results showed that the tungsten carbide bundles distributed in the matrix with the center-to-center spacing 2.2 mm, and the diameter of each tungsten carbide bundle is about 1 mm. Most of the tungsten carbides agglomerated, but still there were tungsten carbide particles and the size of tungsten carbide particle was about 10-15 mu m. The weight loss of the tungsten carbides bundle reinforced iron matrix composites increased with the increase of the loads and the weight loss of the composites is much less than those of the gray cast iron under the same condition. The wear mechanism of tungsten carbide bundles-reinforced iron matrix composites appears as: micro-cutting, micro-ploughing, broken tungsten carbide and broken particles re-embedded in the matrix.