High-temperature Rheological Behavior and Numerical Simulation Technology for 6061 Aluminum Alloy Connecting Rods

Abstract

Aluminum alloy connecting rods formed by common hot forging usually exhibit many surface defects, including cracks, folding, and disordered metal streamlines. These defects can considerably influence their performance. A thermosimulation compression experiment on 6061 aluminum alloy was conducted to prevent such defects and disclose the law of precise forging. The true stress-strain curves and stress peak under different deformation temperatures and strain rates were also obtained. The constitutive equation for the high-temperature rheological stress of 6061 aluminum alloy was derived. On the basis of this equation, the multi-field coupling problem of 6061 aluminum alloy connecting rods during closed forging deformation was discussed, and the influences of three forging techniques on forging results were analyzed. Results demonstrate that 6061 aluminum alloy is sensitive to positive strain rates. Steady-state flow stress is inversely proportional to temperature given a fixed strain rate, and flow stress is proportional to strain rate when the deformation temperature is fixed. During the closed forging process of aluminum alloy connecting rods, the upper and bottom punches move first, followed by the lateral punches, thereby resulting in a notable forging effect. Forging quality is inversely proportional to the movement order of lateral punches. In addition, the forging load of aluminum alloy connecting rods first increases and then decreases and finally increases. Forging load is proportional to deformation rate. The proposed method provides an excellent prospect to determine the closed forging technique of aluminum alloy.