GB799973A - Method of producing shaped bodies from aluminium powder - Google Patents

Abstract

A process for producing shaped bodies such as thin-walled and profiled parts (e.g. ribbons, bearings) from Al powder comprises plastically deforming (e.g. extruding) a mixture of both flaky and nodular Al powders, together with any desired alloying components such as powdered Si, graphite, and intermetallic compounds of Al. The flakes are preferably lenticular with ragged edges, may be be slightly oxidized, and their grease content should be less than 0.4 per cent. Powders both flaky and nodular may be comparatively coarse, e.g. 60 per cent under 40m is useful for bearings. In an example, 39 parts by weight of nodular Al powder with grain size 80 per cent under 40m and with an oxide content of 6 per cent were mixed with 39 parts of lenticular Al powder of which 55 per cent passed a screen of 40m mesh and having an oxide content of 8 per cent. To this mix were added 20 parts of Si powder (60m ) and 2 parts powdered graphite (40m ), and the whole was cold compressed at 2 tons per sq. cm. into shapes of 72 mm. diameter. The shapes were heated for an hour at 440 DEG C., extruded into a channel section suitable for bearings, cut, and forged in forming dies into the finished halves of bearings.ALSO:A process of producing shaped bodies such as thin-walled and profiled parts (e.g., ribbons, bearings) from Al powder comprises plastically deforming (e.g. extruding) a mixture of both flaky and nodular Al powders, together with any desired alloying components such as powdered Si, graphite, and intermetallic compounds of Al. The flakes are preferably lenticular with ragged edges, may be slightly oxidized, and their grease content should be less than 0,4 per cent. Powders both flaky and nodular may be comparatively coarse, e.g., 60 per cent under 40m is useful for bearings. In an example, 39 parts by weight of nodular Al powder with grain size 80 per cent under 40m and with an oxide content of 6 per cent were mixed with 39 parts of lenticular Al powder of which 55 per cent passed a screen of 40m mesh and having an oxide content of 8 per cent. To this mix were added 20 parts of Si powder (60m ) and 2 parts powdered graphite (40m ), and the whole was cold compressed at 2 tons per sq. cm. into shapes of 72 mm. diameter. The shapes were heated for an hour at 440 DEG C., extruded into a channel section suitable for bearings, cut, and forged in forming dies into the finished halves of bearings.