Advanced heat-assisted flexible forming of perforated AZ31B magnesium alloy: a hybrid experimental–numerical study for high-precision biocompatible cranial implant fabrication

Abstract

Single Point Incremental Forming (SPIF) is widely recognised as a flexible manufacturing process for producing complex sheet metal components, particularly in small-batch and customised applications. Magnesium alloy known as a lightweight operational material used mainly in biomedical sector. Current research investigates the formability and surface quality aspects of perforated AZ31B magnesium alloy extended to cranial preparations which has limited formability at room temperature. To overcome this limitation, present work introduces warm heating setup technology aimed to enhance formability of the AZ31B Mg alloy. The study was performed at 400 °C so that the material could deformed till the desired depth of the implant. Identifying a 12 mm tool diameter and a 3.5 mm hole diameter as optimal parameters proves crucial as it yields uniform higher formability and lower surface roughness. Moreover, considering optimal parameters the study finds that a cranial implant, made by zig-zag tool path, 300 mm/min feed rate, and a 0.2 mm step depth, shows both enhanced forming precision and a decrease in surface roughness. Additionally, research investigates changes in microstructure and hardness studies, providing valuable insights into material properties and performance. A finite element model was constructed using the commercial FE-package ABAQUS/Standard. The study investigates von Mises stresses, Plastic equivalent strain, and forming depth across different input parameters.