Abstract: A method of preparing a metal alloy comprising a dispersion of particles of a first metallic material consisting of one or more refractory hard metals in a matrix of a second metallic material includes establishing a molten body of the second metallic material and introducing solid particles of the first metallic material into the molten body. Alternatively solid particles of a metalloid which reacts with the second metallic material to form particles of the first metallic material may be introduced into the molten body. The first metallic material has a higher melting point than the second metallic material and is substantially insoluble therein. The molten body is then stirred at a rate sufficient to effect shearing of the surfaces of the particles such that the surfaces are wetted by the molten body, and the molten body containing the resultant dispersion is cast in any desired manner.

Abstract: A continuous process is described for the production of an aluminum master alloy, e.g. an Al-Ti-B grain refining rod, in which molten aluminum is continuously passed through a confined reaction zone. Particulate titanium and/or boron precursor compounds, e.g. salts, are continuously added to the molten aluminum in the reaction zone and the content of the reaction zone is continuously stirred to submerge the salts within the aluminum melt and form an alloy therewith. A mixture of formed molten alloy and entrained reaction products is continuously transferred from a lower region of the reaction zone into a refining zone, with reaction product slag being collected on the surface of the molten alloy in the refining zone. The molten alloy formed is continuously transferred via a transfer conduit from the refining zone to a casting station.

Abstract: The invention provides a method of removing inclusions from molten metal, particularly aluminum, by(a) contacting the molten metal with a medium which retains metal-non-wettable inclusions. The medium may be liquid such as a fused salt mixture; or solid such as a filter or metal-non-wettable ceramic materials or a bed of granules e.g. of tabular alumina,(b) passing the molten metal through a filter of metal-wettable material, e.g. a refractory hard metal such as titanium diboride. The metal-wettable filter attracts and holds metal wettable inclusions within itself, and may also prevent by surface tension the entry of fused salt droplets.

Abstract: A cermet material comprises an intergrown network of a minor proportion of ceramic such as TiB.sub.2 in a metal matrix such as Al. The cermet is prepared by forming a minor proportion by weight of a ceramic phase in situ in a molten metal phase and holding the mixture of elevated temperature for a time to effect formation of an intergrown ceramic network.

Abstract: A method of producing an aluminum boride (AlB.sub.2 or AlB.sub.12) in solid form comprises providing a body of molten aluminum containing suspended particles of an aluminum boride, and separating the particles e.g. by filtration from the bulk of the molten metal. Preferred filter media are alumina and carbon, each of which can be subsequently removed to leave the aluminum boride in solid form. The product is a useful precursor for production by reaction sintering of refractory composites containing titanium diboride.

Abstract: A method of making a refractory material, e.g. suitable for use in lining Al electrolytic cells, comprises passing molten Al containing suspended particles of a transition metal diboride (e.g. TiB.sub.2) through a refractory filter, on and in which the particles are deposited. The filter can be used as it is, or compressed and sintered, or comminuted and formed into bodies. The concentration of the diboride may be at least 25% on the upstream surface of the filter but progressively reduced with increasing distance from that surface.