Such alloys tend to have grains of {HEAD ~ excessive size} which can lead to {TAIL ~ brittle castings} 
lead to
Such alloys tend to have grains of { HEAD ~ excessive size } which can lead to { TAIL ~ brittle castings }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL