• Smith, Mike C.
• Flint, Tom
• Francis, John A.

Abstract

The accurate prediction of transient temperature fields, induced in alloy<br/>systems during advanced manufacturing processes, is critical. These fields influence the magnitude and distribution of residual stresses, the evolution of<br/>material microstructures, and material properties such as fracture toughness.<br/>Such predictions in the vicinity of a concentrated heat source requires precise<br/>knowledge of the associated heat flux as a function of position and time. If<br/>the applied thermal load is time-dependent this can have a significant effect<br/>on the resulting temperature fields and microstructures. In this work a novel<br/>three-dimensional heat source is proposed to represent the friction stir welding<br/>process along with the semi-analytical solution for the temperature field. The<br/>volumetric heat source model has a nontrivial spatial distribution constructed<br/>from physical arguments and may account for complex mass transfer, and the<br/>associated thermal effects, without explicitly solving the flow equations. A<br/>method for incorporating a time-dependent heating scenario into analytical so-<br/>lutions generated by this heat source is also presented. Predicted temperatures<br/>are compared with those measured experimentally for two cases reported in<br/>the literature and good agreement is observed. Example solutions for various<br/>time-dependent heat inputs are also presented.

Topics

• impedance spectroscopy
• microstructure
• simulation
• thermal analysis
• fracture toughness