1. Forged aluminum alloy has low plasticity. The plasticity of aluminum alloy is greatly affected by alloy composition and forging temperature, and the sensitivity of plasticity to deformation speed varies with the content of alloy elements. When the content of alloying elements increases, the plasticity of the aluminum alloy continues to fall and is sensitive to the deformation speed. The level has also improved. Most aluminum alloys are positive strain rate sensitive materials, that is, the active stress decreases as the deformation rate decreases. Therefore, large-scale aluminum alloy forgings used in aviation are usually formed by hydraulic or hydraulic presses, while small- and medium-sized aluminum forgings can be manufactured using screws, presses or mechanical presses.
2. Forged aluminum alloy has strong adhesion. Because aluminum and iron can be solid-solved, aluminum alloy often sticks to the mold during the forging process. It is generally believed that the spindle oil can have a better smoothing effect. In recent years, American companies such as Acheson have also developed aluminum alloy smoothing agents suitable for industrial applications. There are also domestic companies that formulate their own oil-based or water-based smoothing agents with very good results.
3. The narrow forging temperature range of forged aluminum alloy. The forging temperature range of most aluminum alloys is within 150°C, and some even as long as 70°C. Therefore, in the production of aluminum forging and forging, a variety of heating methods are often required to ensure that the aluminum alloy has good forgeability. Especially for aerospace and military products that have strict requirements for product performance, aluminum and aluminum parts are usually processed by isothermal forging during final molding.
4. The deformation of forging aluminum alloy is small. Aluminum forging usually does not allow small processes and large deformations to prevent coarse crystals or cracks. Therefore, it is often necessary to allocate the total deformation reasonably. The billeting process has a greater impact on the forming result of the final product. After repeated procedures, the temperature of the workpiece is usually lower than the required forging temperature, so it needs to be heated again.