Abstract: A fabric knitted from a precious metal fibre, especially platinum or palladium or alloys thereof, offers advantages as a catalyst gauze, for example in ammonia oxidation. A method for knitting at high weights involves the co-feeding of a supplementary fibre with the metal fibre.

Abstract: A fabric knitted from a precious metal fibre, especially platinum or palladium or alloys thereof, offers advantages as a catalyst gauze, for example in ammonia oxidation. A method for knitting at high weights involves the co-feeding of a supplementary fibre with the metal fibre.

Abstract: In a continuous friction-actuated process for the extrusion of copper, a passageway 3 is formed between an arcuate first member and a second member in the form of a wheel 1 having a circumferential groove 2 formed in its peripheral surface into which groove the first member projects. The wheel is rotated and metal is fed into the passageway at one end and extrudes from the passageway through at least one die orifice 6 located in or adjacent to an abutment member 5 extending across the passageway at the other end thereof. The abutment member is of substantially smaller cross-section than the passageway so as to leave a substantial gap between the abutment member and the groove.

Abstract: In a modified "Conform" machine for continuous friction-actuated extrusion of metals, especially particulate copper, the abutment at the outlet end of the working passageway does not fully block the end of the wheel groove. Instead a substantial clearance is left, and metal extruding through it adheres to the wheel to re-enter the working passageway at the entry end. Preferably the abutment is of semicircular cross-section. For a given output rate, a significant reduction in torque, and working stresses, is obtained.

Abstract: In continuous friction-actuated extrusion, especially Conform extrusion of copper, at least part of the tooling is made from aged nickel-chromium base alloy (which is preferably cold-worked before aging to give a yield strength of at least 1500 MN/m.sup.2 at 20.degree. C.) and which is capable of sustaining an adherent oxide film. The preferred alloy is "Inconel Alloy 718". Despite lower hardness, the tooling has better service life than conventional special-steel tooling.

Abstract: In a modified "Conform" machine for continuous friction-actuated extrusion of metals, especially particulate copper, the abutment at the outlet end of the working passageway does not fully block the end of the wheel groove. Instead a substantial clearance is left, and metal extruding through it adheres to the wheel to re-enter the working passageway at the entry end. Preferably the abutment is of semicircular cross-section. For a given output rate, a significant reduction in torque, and working stresses, is obtained.