|About this Abstract
||NUMISHEET 2021: The 12th International Conference on Numerical Simulation of 3D Sheet Metal Forming Processes
||Die Quench Thermal and Friction Boundary Conditions
||Raphael Boulis, Sante DiCecco, Ryan George, Michael Worswick
|On-Site Speaker (Planned)
The die-quench (DQ) sheet metal forming process entails simultaneous forming and rapid quenching of precipitation-hardenable aluminum blanks from solutionization temperatures of upwards of 470°C using cold tooling. Accurate modelling of the heat-transfer process during the entire forming operation, from blank transfer to forming and quenching, ensures that sufficient quench rates can be achieved to maximize the artificial aging response, and thus final strength properties, post-forming. In this work, coupon level experimental testing was completed to determine the heat transfer properties of an AA7075 2 mm thick sheet alloy for the process conditions of pressure and applied lubrication. Coupon level testing was also completed to characterize the friction at the interface for different pressures, lubricants and sliding speeds using a twist-compression testing (TCT) apparatus. A numerical parametric study was completed to calibrate a suitable heat-transfer model using the experimental data to quantify the significance of different heat transfer parameters, such as the thermal activation gap value, commonly used within the LS-DYNA framework. The calibrated heat-transfer model along with friction results were applied in the modelling of the DQ forming of a representative vehicle component to characterize quench rates and forming temperatures and their effects on the subsequent artificial aging response as well as evaluate the localized thinning of the material.
||Definite: At-meeting proceedings