Speaker
Description
EN-AW-6016 sheet material is highly demanded for automotive applications due to its balanced properties of formability, strength, and corrosion resistance. Formability is characterized by the anisotropy of the sheet (r-value) and the ability to allow flat hems without surface cracks. The thermal history of the hot band, including ingot preheating and hot rolling, is crucial for the final properties. Alloy 6016 contains high levels of Si,leading to pure Si precipitates alongside Mg2Si. Ingot preheating temperature affects the amount of Si and Mg in solid solution, while the hot rolling cooling rate influences the size of Si and Mg2Si precipitates. Coarse particles can enhance particlestimulated nucleation (PSN), reducing Cube texture. Reduced Cube texture benefits lower planar anisotropy (Δr) for deep drawing but can be detrimental for hemming.
Three hot bands with varying sizes of Si and Mg2Si precipitates were produced by AMAG. Despite similar production steps after hot rolling, the final sheet material showed equal strengthand elongation, but differences in r-value and hemming behavior due to texture variations. Effective hemming is essential in the production of automotive doors and closures to prevent surface cracks and ensure the aesthetic quality of the components.