From: The effect of pin profiles on the microstructure and mechanical properties of underwater friction stir welded AA2519-T87 aluminium alloy
Pin profile
SZ (μm)
AS-TMAZ (μm)
RS-TMAZ (μm)
RS-HAZ (μm)
PM (μm)
FSW-THC
17.5
85
64
49
FSW-TTC
15
82
60
UWFSW-THC
5.2
54
52
UWFSW-TTC
3.3
50