The Superplastic Forming of Bulk Metallic Glasses

Superplastic forming (SPF) is introduced in this article as a net-shape processing method for bulk metallic glasses (BMGs), commercially known as Liquidmetal® alloys. This method decouples fast cooling and forming of the BMG. Forming takes place in the supercooled liquid region, where the BMG exists as a highly viscous liquid and increases its fl uidity with increasing temperature. The SPF method is very similar to techniques used for processing thermoplastics. In this work, a simple fl ow law is used to quantify the forming ability and to estimate both the potential and the limitations of the SPF method. This process is especially well suited to replicate small features and thin sections with high aspect ratios, which makes this process appropriate for microelectromechanical systems, nanoand microtechnology, jewelry, medical and optical applications, and data storage.