The mechancial properties and metallographic structure of Al 12Si 2Cu alloys with 0.1

0

.25 wt% mischmetal have been investigated on the gravitational and pressure casting samples. The fluidity of the liquid alloys and thermal cracking stress of the alloys in solidification determined.It was shown that if additional 0.1

0

.25wt% mischmetal is added to the Al-12Si-2Cu alloy

the primary a Al phase will be preferentially formed

and the eutectic silicon phase will be informed of a small bar or a particle

but not a needle. As a result

the strength and the elongation of the alloy were increased and the resistance to thermal cracking was obviously improved.