The hypothesis that the retention of Al and O at grain boundaries and {TAIL ~ triple points} would result in {HEAD ~ high fracture toughness} was not correct 
The hypothesis that the retention of Al and O at grain boundaries and { TAIL ~ triple points } would result in { HEAD ~ high fracture toughness } was not correct
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH