Deep Drawability of Al-Mg Alloys Produced by Twin Roll Continuous Casting Method: Investigation of Microstructure and Mechanical Properties

Abstract

This study explores the development of Al-Mg alloy sheets manufactured through the Twin Roll Continuous Casting (TRC) technique, with the goal of enhancing their mechanical properties via thermomechanical processing. TRC is a cost-effective and efficient method for producing thin sheets directly from molten metal, and this work focuses on the deep drawability of AA5182, AA5754, and AA5052 alloys, widely used in automotive, packaging, and aerospace applications. Improving deep drawability is crucial for meeting the stringent requirements of these industries. The alloys were designed according to EN 573-3 standards, and sheet castings were carried out at both laboratory and industrial scales. Microstructure evolution was analyzed at the as-cast and final thicknesses using optical microscopy. The sheets underwent cold rolling to a thickness of 1 mm, followed by final annealing, and their mechanical properties—including yield strength, tensile strength, elongation, and anisotropy—were evaluated. The deep drawability of the sheets was assessed using Erichsen cupping tests and earing mechanisms. To further understand failure mechanisms, fracture surface morphologies were examined using scanning electron microscopy (SEM), while energy-dispersive X-ray spectroscopy (EDS) was performed to analyze inclusions on fractured surfaces. The findings highlight the effectiveness of the TRC technique in producing high-performance Al-Mg sheets with mechanical properties comparable to or exceeding those of conventionally processed sheets. This study provides valuable insights into the optimization of alloy design and manufacturing methods, laying the groundwork for future advancements in TRC technology.