Experimental verification of an impinging molten metal droplet numerical simulation
- Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Mechanical Engineering
Numerical modeling techniques and experimental verification have been used to investigate the remelting of a substrate by a molten metal droplet landing and solidifying on the substrate. understanding the phenomenon of droplet/substrate bonding is relevant to a manufacturing process being developed at Carnegie Mellon University, called Shape Deposition Manufacturing microcasting, where successive layers of molten metal material are deposited to form three-dimensional objects. By remelting a thin layer of the solid substrate, an impinging droplet creates a stronger, metallurgical bond that greatly improves the deposited material properties. A combination of methods is required to optimize the process and ensure remelting, including a numerical approach due to the extreme thermal conditions of the process, analytical determination of the initial interface conditions, and experimental verification. Experiments validating the numerical results and determining the process operating conditions include calorimetry and thermocouple measurements, metallographic characterizations, and droplet pattern tests. Experiments have shown that despite the two-dimensional nature of the microcast droplets, a one-dimensional numerical model provides accurate information regarding the initial stage of the process relevant to remelting. Initial agreement between experimental droplet cooling and the numerical results also indicates that conduction heat transfer and latent heat release from the droplet to the substrate dominates over any convective effects during the solidification and cooling process. Substrate remelt depths measured from micrographic examinations compare well with the numerical simulations of droplet solidification, and droplet spreading patterns on various substrate materials concur with the analytical and numerical predictions.
- OSTI ID:
- 458416
- Report Number(s):
- CONF-951135--; ISBN 0-7918-1751-2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Modeling of molten droplet impingement on a non-flat surface
Numerical investigation of micro-pore formation during substrate impact of molten droplets in spraying processes