Abstract
A critical assessment of various solid-state-bonding mechanisms is established for friction stir welding (FSW) processes of engineering alloys. The commonly assumed sintering-like diffusional-bonding hypothesis is criticized in this work as not the dominant mechanism. For the wide spectrum of material constitutive laws and FSW processing conditions examined and employed in realistic applications, the thermomechanical history on the workpiece–workpiece interface traverses in the creep-dominated regime for the growth/shrinkage of interfacial cavities. The evolution of the bonding fraction relies mainly on the creep strain rate in the adjourning workpieces, weakly on stress triaxiality, and negligibly on interfacial diffusion.
| Original language | English |
|---|---|
| Article number | 100727 |
| Journal | Extreme Mechanics Letters |
| Volume | 37 |
| DOIs | |
| State | Published - May 2020 |
Funding
The authors would like to acknowledge the Manufacturing and Materials Joining Innovation Center (Ma 2 JIC), made possible through IIP-1540000 and IIP-1822186 from the US National Science Foundation , Industry University Cooperative Research Center (I/UCRC) program , to the University of Tennessee for financial support. XW and YG are grateful to fruitful discussions with Dr. Wei Zhang at ORNL, and to the partial support from the Center for Materials Processing at the University of Tennessee .
Keywords
- Creep-controlled cavity closure
- Friction stir welding
- High temperature bonding