Abstract: In methods of joining metal surfaces involving heating to a temperature above about 560.degree.C, the use of a flux comprising a mixture of potassium fluoaluminates. Particularly for brazing aluminum, a flux consisting essentially of potassium fluoaluminate complexes (e.g. KAlF.sub.4 and K.sub.3 AlF.sub.6) may be employed, having a composition corresponding to an AlF.sub.3 /KF ratio, in parts by weight, between about 65:35 and about 45:55. The flux is essentially free of unreacted potassium fluoride and may be in divided solid form.

Abstract: A riveting apparatus comprises first and second dies having plane forward end faces for gripping a workpiece over a substantial area round the location to be riveted. The dies have aligned bores which open to said end faces and which are the same as each other in cross section, and a punch and a plunger corresponding to the shape of the bores are slidably mounted in the bores of the first and second dies respectively. A hydraulic piston operates the punch and the forward movement of the punch along the bore of the first die can be terminated by a stop selectively either with the punch and flush with or a predetermined distance short of the end face of the first die. The plunger can be moved hydraulically along its bore toward the punch. In operation of the apparatus, a headless pin is driven through an imperforate workpiece and thereafter each end of the pin is upset while the pin is prevented from moving lengthwise of itself relative to the workpiece.

Abstract: In the direct chill semi-continuous casting of an ingot of rectangular cross-section, the formation of convexly curved surfaces on the wider faces of the ingot is avoided, along the full length of the ingot, by progressively increasing the gap at least between the mid-points of the longer sides of the rectangular mould, without substantially altering the gap between the ends of said sides, as the rate of advance of the ingot through the mould increases from a relatively low initial speed. The mould is cooled and coolant is applied directly to the surface of ingot emerging from the mould. In an apparatus for putting the above method into practice, means is provided for varying the curvature of the long side walls of the mould progressively during a casting operation by the application of a flexing force arranged symmetrically with respect to the mid-point of each of the long sidewalls, the ends of the said side walls being restrained from transverse movement.

Abstract: In the casting of aluminium and other metals having a relatively low melting point, the metal is cast between a pair of belts, which are caused to move along precisely defined paths by means of externally applied attractive forces, which hold the outer surface of at least the upper of the belts against closely spaced support surfaces. The attractive force is preferably achieved by sub-atmospheric pressure conditions on the reverse side of the belts, although magnetic forces may be employed for the same purpose. The belts are preferably arranged to provide a casting cavity of decreasing thickness to maintain close contact between the belt and the solidifying metal to secure rapid transfer of heat from the metal to the belts throughout the length of the casting zone. The cooling of the belts is preferably achieved by directing jets of coolant substantially normally to the belt at closely spaced localities.

Abstract: Apparatus for circulating molten metal in a furnace comprises an electromagnet the coil of which is adapted for energisation from an alternating current source and the core of which is elongate and projects from both ends of the coil. The core is disposed so that 25% to 50%, preferably 37%, of its length is at one axial side of the mid-point of the coil, and the part of the core projecting at the said one axial side of the coil has a coating or casing of a refractory material. The apparatus may be mounted with its core horizontal in a side wall of the furnace but it is preferred to dispose the core vertically with the heat shield close to the surface of the molten metal. A duct member may surround said part of the core and may be shaped to direct the molten metal laterally. A partition or other form of baffle may be disposed externally of the duct between the inlet and outlet of the duct to prevent the molten metal leaving the outlet of the duct from passing straight back to the inlet of the duct.

Abstract: In making carbon bodies for lining aluminum reduction cells, an aggregate including carbon recovered from used linings of such cells is mixed with binder material incorporating an alkaline-catalyzable furan binder. Residual contaminant material in the recovered carbon acts as a catalyst for the furan binder, so that the binder-aggregate mixture constitutes a self-hardening carbon lining body.