Closed Die Forging Geometrical Parameters Optimization for Al-MMC

Abstract

Demand for lighter and stiffer products has been increasing in the last few years especially in automobile manufacturing. The closed die forging process of Metal Matrix Material (MMC) is presented as possible solution, since it produces parts with good mechanical properties and lighter weight. A computational modeling of closed die forging process using finite element method and optimization techniques makes the design optimization faster and more efficient, decreasing the use of conventional trial and error methods. In this study, the application of commercial finite element software (ANSYS) has been used to model cold closed die forging process. The model has been developed using ANSYS Parametric Design Language (APDL) to simulate a single stage axi-symmetry closed die forging process for H cross sectional shape. The material used is AlMgSi matrix with 15% SiC particles. Its flow curve and fractural strain are obtained from the literature. ANSYS Optimizer is used to obtain the maximum height in which the material can flow in the rib by changing Design Variables (DV) and State Variables (SV). Normally design variables are geometrical parameters such as, rib height to width ratio, web height to rib height ratio, fillet radii, draft angle and billet radius. State Variables (SV) are some parameters that depend on the design variables such as, the equivalent strain which must be below the fracture strain of the MMC material, and an acceptable contact gap (within the allowable tolerances range). Optimization method called Sub-Problem Approximation Method was used to find out the optimal design set. The technique used in this study can be used for newly developed materials to investigate its forgeability for much complicated shapes in closed die forging process.