Synthesis of Ultrafine ZrC Powders by Novel Reduction Process

Abstract

Zirconium carbide (ZrC) is becoming a promising hard material for high-temperature applications in the tool and nuclear energy industries. There are few methods for fabricating micrometric ZrC particles including the carbothermal reduction of zirconium dioxide and direct exothermic reaction of pure zirconium and graphite powder. A novel reduction method has been developed in this study to fabricate ultrafine ZrC powders using ZrCl₄ and carbon black as source materials and sodium bicarbonate (NaHCO₃) as a reductant. Simple rotation ball-milling was used to reduce the Cl-components in zirconium chloride by the sodium component in sodium bicarbonate, leading to the formation of non-toxic and stable sodium chloride. ZrC particles 150 nm in size were successfully obtained after heat treatment at 1673 K. The carbon content in the product could also be controlled by changing the initial carbon fraction.