Analysis of Material Characteristics and Forging Parameters for Flashless Forged Aluminum-Matrix Composites

Recent research dealt with the basic forgeability of aluminum-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 analyzed. This paper describes the combination of mechanical advantages of aluminum-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 metal-matrix composites (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. Finite Element (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.