Characterization of Sintered Aluminium Reinforced with Ultrafine Tungsten Carbide Particles

Abstract

The strengthening e ect on aluminium (Al) by ultrafine particles of tungsten carbide (WC) after compacting and sintering was evaluated. The Al-1 vol.% WC mixture was prepared through a high-speed stirring technique, called assisted sonication. In this study, the e ects of compacting, sintering temperature and holding time were evaluated by composite microstructural characterization and by mechanical tests. The characterizations involved electron dispersive spectroscopy and X-ray di raction techniques for phase identification; electron backscattered di raction for crystallographic analysis; backscattered electrons and secondary electrons imaging for failure and wear studies. In all composites, hardness was determined; for the hardest composite, the tensile strength, flexural strength and ball scattering wear resistance were also evaluated. The Al-1 vol.% WC composite produced by assisted sonication, densified by cold compacting at 152 MPa and sintered at 640 C for 2 h at 5 10􀀀4 Pa (high vacuum) exhibited the highest hardness, associated with an acceptable ductile behavior. This strengthening was associated with the formation of Al12W and grain refinement.