Flashless forging of aluminum matrix composites

The strength/density ratio of aluminium can be increased significantly by the integration of ceramic particles in the metal matrix, so called Aluminum MMC. Because machining of MMCs is very expensive due to the high hardness of the ceramic particles precision forging of Aluminum MMCs allows the high quantity production of near net shape components with a strength/density ration. The paper describes the development of a precision forging sequence for a demonstration made of Aluminum MMC.

aluminium metal matrix composites, flashless forging, FEA

Recent research dealt with the basic forgeability of aluminium-matrix composites produced under laboratory conditions. These research projects concentrated on metallurgy and, by deriving flow curves, on formability. In contrast to laboratory conditions, the industrial use requires large batches of raw materials and takes place under real conditions. Those conditions have not yet been analysed. This paper describes the combination of mechanical advantages of aluminium-matrix composites and a flashless forging process. The advantages can be outlined as higher part strength, compared to conventional forging parts with the same weight. Newly derived flow curves demonstrate formability and were used to evaluate basic forging parameters. The first forging trials in a conventional forging process using a high forging rate resulted in broken parts and therefore required a reduced deformation rate. The matrix slug material provides a higher deformation rate but has to be reduced, due to the use of MMCs. Using a conventional forging press (e.g. screw press) causes material failures likes cracks, because forging Al-MMCs requires a reduced forming speed of 20 mm/s. Reducing the forming speed, hydraulic presses are recommended. FE-analysis of the newly developed flashless forging process is described and depicts the basic forming operations (spreading, elongating and climbing) of the material in the forging die. Altogether a new strategy for a flashless forging process layout with Al-MMC is shown.

forging, flashless, aluminium, matrix, composite, characterization, upsetting, FEA, simulation, tool

Aluminum Metal Matric composites show a high strength/density ratio. These materials can combine the advantages of aluminum and ceramic. A research project at IPH investigated the precision forging of Aluminum MMC to establish forging processes for Aluminum MMC and to allow a high batch production.

aluminium metal matrix composites, FEA, flashless forging