Friction stir welding is preferred for aluminum-lithium alloy rocket tanks because it produces _______ joints than fusion welding.
- weaker
- stronger and defect-free
- heavier
- more porous
Answer: stronger and defect-free
FSW solid-state process avoids melting/solidification defects, yielding superior mechanical properties for cryogenic tank structures in PSLV/GSLV/LVM3.