Microstructural changes during tension of friction-stir welded AZ31 magnesium alloy

The twin-induced 0001<112¯0> orientation was shown to promote double {101¯1}-{101¯2} twinning which is known to lead to final failure. It was therefore suggested that the cause of the well-known premature fracture of magnesium welds at the stir zone extremity may be due to the profuse {101¯2} twinning.