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Process route for elevated temperature aluminium alloys

The processing route involves the inert gas atomization of potential elevated temperature aluminium alloys. Aluminium iron vanadium alloys are produced in the form of rapidly solidified, fine (less than 45 um) powders. The powders are then cold compacted to approximately 90% theoretical density. These green compacts are then rapidly heated (less than 5 min) by induction heating, to the appropriate hot working temperature (450 to 500 C). The hot compacts are then extruded into fully dense rods, tubes or strips which are immediately quenched on exit from the extrusion die. If the product is required in sheet form the extruded strip can be reheated (rapidly) and then hot rolled. This route facilitates the production of aluminium alloys containing homogeneous dispersions of stable second phase particles which impart excellent engineering properties in the potential service temperature range 150 to 300 C. By minimizing both the consolidation temperature and the time for which the material is exposed to this temperature, coarsening of the second phase particles is minimized leading to improved elevated temperature properties in service. This processing route also eliminates the need for costly and time consuming hot, vacuum degassing operations which, at present, are used in most other rapid solidification processes.

This processing route also lends itself to further improvement in terms of production costs, efficiency and product quality. These goals may be obtained by fully integrating the individual processing stages into a semicontinuous production line in which the compaction and preheating stages are replaced by a single fluidized bed process.

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