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In this paper the influence of the Ni binder metal and Al as an additional alloying element on the microstructure and mechanical properties of WC-based cemented carbides processed by conventional powder metallurgy was studied. Microstructural examinations of the cemented carbides with 3 and 5 wt.% of Al in the binder metal indicated the presence of a very low and evenly distributed porosity as well as the presence of islands of metal binder in the microstructure. With the cemented carbide with 7 wt.% of Al in the metal binder, the presence of brittle needle-like regions was observed. The WC particles inside these regions were rounded and had a larger mean free path. Vickers hardness and flexural strength tests indicated that the cemented carbide WC-Ni-Al with addition of 5 wt.% of Al in the binder metal presented bulk hardness similar to the conventional WC-Co cemented carbides as well as superior flexure strength and fracture toughness.

In this work the surface of ductile iron is hardened by a tungsten carbide (WC) layer. The inserted layer is obtained by pouring liquid cast iron on a mixture formed by WC particles (with an average diameter of 6 micrometers) and sodium silicate (acting as a binder). Results show that a sound inserted layer with 2.5mm thickness was produced; the layer is compact, the interstices between particles (with dimensions close to some tenth micrometer) are filled with base metal and the continuity between the WC particles and the base metal is ensured by growth of tungsten rich carbides from the WC particles into the metallic matrix. The surface hardness of the inserted layer achieves Fig.s higher than 500VHN/4.9N.