Laser additive manufactured WC reinforced Fe-based composites with gradient reinforcement/matrix interface and enhanced performance

Laser additive manufacturing has been proved to be a new technology for production of high-performance metal matrix composites with tailored interfacial structures. The WC particle reinforced Fe-based composites were manufactured by selective laser melting to investigate the effects of laser processing parameters on densification, microstructure and mechanical properties. The densification level increased with increasing laser power and decreasing scanning speed. The novel gradient interface formed around WC particles due to the in-situ reaction between WC particle and Fe-based matrix. After the optimization of laser processing conditions, the micro-hardness enhanced to 511.6 HV0.2 and a low friction coefficient of 0.30 was achieved with a low wear rate of 3.1 × 10−5 mm3/(Nm). The improvement in wear performance attributed to the synergistic effect of gradient interface, enhanced densification and novel microstructure.