The invention relates to the technical field of
cemented carbide preparation, in particular to surface-hardened gradient
cemented carbide and a preparation method thereof. By adjusting components of an
alloy binding phase, the WC crystalline grains in the prepared
cemented carbide are small, even in distribution, high in density and remarkable in gradient, the cemented
carbide is made to have the more excellent
mechanical property, and the red
hardness of the cemented
carbide is improved. The components and thickness of a gradient layer of the cemented
carbide are controlled by adjusting blank formulas,
sintering temperature,
sintering time and other parameters, the
surface layer of the cemented carbide is made to be rich in cubic phase and poor in binding phase, and due to the fact that a
transition layer rich in alloying binding phase is arranged below the
surface layer, the cemented carbide is excellent in
hardness,
wear resistance and roughness, and the cemented carbide can be used for
metal machining. The cemented carbide prepared through the method has the excellent
wear resistance, strength,
hardness and
toughness at the same time. According to the method, the functional gradient cemented carbide can be produced by slightly modifying existing equipment and processes, and is suitable for industrial production.