Multi-objective Optimization of Process Parameters for 7050 Aluminum Alloy Rib-web Forgings’ Precise Forming based on Taguchi Method

AbstractThe precision forming of rib-web forgings can effectively increase strength and toughness of forgings and improve material utilization simultaneously. However, inappropriate selection of process parameters can cause defects such as under-filling, cross flow, and etc. Thus the optimization of process parameters is essential for getting good products. In this paper, we combined the finite element method with Taguchi method to optimize the precision forming process of rib-web forgings through multi-objective design. The macro-and microstructure of products were used to verify the result of simulation. The flow line microstructure and the die-fill quality were chosen as optimal objectives; and, the optimal combination of parameters for the analyzed process window was obtained through the variance analysis and signal-to-noise ratio analysis of the simulation results. The results suggest that initial temperature and height-width ratio of the billet are the most crucial factors affecting the forging quality in the analyzed area. In addition, the optimal combination of parameters is A4 (450°C) B1 (0.1mm/s) C4 (H / B =5) and D3 (μ = 0.3). Finally, the production experiment verified the prediction quite well, which confirmed the effectiveness of the proposed optimization method