Microscale Thermoplastic Forming of Bulk Metallic Glasses: Numerical Simulation and Experiments
- PDF / 706,878 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 89 Downloads / 165 Views
1048-Z04-05
Microscale Thermoplastic Forming of Bulk Metallic Glasses: Numerical Simulation and Experiments David Henann, and Lallit Anand Mechanical Engineering, MIT, Cambridge, MA, 02139 ABSTRACT An extremely promising microscale processing method for bulk metallic glasses called thermoplastic forming has emerged in recent years. However, most of the recent experimental thermoplastic forming studies have been conducted by trial-and-error. In this paper, we use the large-deformation constitutive theory of Henann and Anand [1] as a numerical simulation tool for the design of a micro-hot-embossing process. This numerical simulation capability is used to determine appropriate processing parameters in order to carry out a successful micron-scale hotembossing operation on the metallic glass Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vitreloy-1). By carrying out a corresponding physical experiment, we demonstrate that micron-scale features in Vitreloy1 may be accurately replicated under the processing conditions determined by use of the numerical simulation capability. INTRODUCTION In recent years, a promising thermoplastic forming process geared towards producing nano/microscale, high-aspect ratio, patterned features on bulk metallic glass (BMG) surfaces is that of micro-hot-embossing. In this process, the BMG is formed in its supercooled liquid region by pressing it against a master-surface with the desired nano/microscale features (usually a patterned silicon wafer). The viability of this process has been demonstrated extensively in the literature [cf., e.g., 2, 3, 4, 5, 6, 7]. However, as with any emerging technology, the scientific basis for this process is at present fragmented and limited. The design of micro-hot-embossing processes would be facilitated by a mechanics-based numerical simulation and design capability. In a recent paper, Henann and Anand [1] have extended the constitutive framework of Anand and Su [8, 9, 10] to represent the mechanical response of metallic glasses in the temperature range 0.9θg
Data Loading...
