COMPARISON OF FLOW PATTERNS BETWEEN PLASTICINE AND ALUMINUM-ALLOYS INHOT-PRECISION FORGING

Flow patterns, folding problems and die filling in hot precision forgi ng of aluminium alloys are simulated by physical modelling using plast icine. In order to study the reliability of the simulation, a forged p roduct of complex geometry has been chosen. It is found that only the correct direction of the layers of the stacked plasticine blanks can h ave a similar folding problem as that in alloy products. The fracture mode caused by temperature rise due to plastic deformation in an alumi nium workpiece cannot be found in the compression of plasticine. Becau se the forgeability of plasticine is much better than that of aluminiu m alloys, the simulation of die filling cannot provide correct informa tion for the hot precision forging of aluminium alloys. Moreover, the surface finish in hot precision forging cannot be simulated by physica l modelling. (C) 1997 Elsevier Science S.A.