Selection and Investigation of Thermoplastic Materials as Forming Tools for Warm Dry Forming of Magnesium and High-Strength Aluminum Sheets

The growing demand for lightweight components has highlighted the potential of sheet metal parts made from high-strength aluminum and magnesium alloys. However, the forming of these materials is often limited by complex manufacturing processes that typically require lubricants, raising environmental and economic concerns. This study investigates the feasibility of using thermoplastic polymers as tooling materials for dry forming of aluminum alloy 7075-T6 and magnesium alloy AZ31B at temperatures up to 300 °C. A number of high-performance thermoplastic polymers were selected based on their superior mechanical and thermal properties and evaluated through compression and tensile tests, dilatometry, pin-on-disk and strip drawing tests. In addition, the influence of coatings on the tribological performance of the polymers was systematically investigated. The results showed that thermoplastic tools have the potential for efficient dry forming of AA 7075-T6 and AZ31B parts at temperatures up to 300 °C, achieving good tool stability, wear resistance and part quality. TECAPEEK PVX with original tribological optimization proved to be the most promising candidate and was validated in challenging cross cup forming experiments. This lubricant-free approach offers significant environmental and economic benefits, providing a sustainable solution for prototyping and small-scale production of lightweight metal components.