Numerical simulation of three-dimensional heat transfer and plastic flow during friction stir welding

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 37; no. 4; pp. 1247 - 1259
• Main Authors: NANDAN, R, ROY, G. G, DEBROY, T
• Format: Journal Article
• Language: English
• Published: New York, NY Springer 01.04.2006; Springer Nature B.V
• Subjects: 3-D graphics; Applied sciences; Exact sciences and technology; Friction stir welding; Heat transfer; Joining, thermal cutting: metallurgical aspects; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Viscosity; Welding; Flow welding; Plastic flow; Friction; Plasticity; Mechanical properties; Heat flow; Numerical simulation; Friction welding; Heat transfer
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-006-1076-9

Three-dimensional visco-plastic flow of metals and the temperature fields in friction stir welding have been modeled based on the previous work on thermomechanical processing of metals. The equations of conservation of mass, momentum, and energy were solved in three dimensions using spatially variable thermophysical properties and non-Newtonian viscosity. The framework for the numerical solution of fluid flow and heat transfer was adapted from decades of previous work in fusion welding. Non-Newtonian viscosity for the metal flow was calculated considering strain rate, temperature, and temperature-dependent material properties. The computed profiles of strain rate and viscosity were examined in light of the existing literature on thermomechanical processing. The heat and mass flow during welding was found to be strongly three-dimensional. Significant asymmetry of heat and mass flow, which increased with welding speed and rotational speed, was observed. Convective transport of heat was an important mechanism of heat transfer near the tool surface. The numerically simulated temperature fields, cooling rates, and the geometry of the thermomechanically affected zone agreed well with independently determined experimental values. [PUBLICATION ABSTRACT]