A REVIEW ON THE EFFECTS OF THE REDUCTION RATIO AND THE DIE ANGLE ON THE PROPERTIES OF EXTRUDED Al-Zn-Mg ALLOY

Extrusion is a widely used technique in processing Al-Zn-Mg alloys due to its efficiency, cost-effectiveness, and ability to enhance mechanical properties. This study examines the effects of two critical extrusion parameters namely, reduction ratio and die angle on the mechanical and microstructural behavior of these alloys. Studies show that increasing the reduction ratio from 8:1 to 24:1 significantly refines grains, boosts tensile strength by up to 30%, and increases hardness through enhanced plastic deformation and dynamic recrystallization. However, excessively high ratios may cause tool wear and reduced ductility. Smaller die angles of 15°–30° yield more uniform deformation and finer grains, improving strength and hardness. Die angles greater than 60° increase extrusion pressure, decrease stability, and may impair performance. Optimal results of tensile strength exceeding 400 MPa and elongation over 10% are achieved at die angles of 30°–45° and reduction ratios of 16:1–20:1. This review provides a novel synthesis of parameter-property relationships, offering valuable insights for optimizing extrusion conditions to achieve superior mechanical properties in Al-Zn-Mg alloys.