By comparing the microstructure and mechanical properties of gypsum mold precision castings with different process conditions

the effects of the shrinkage porosity defects on mechanical properties of thin-wall plate samples of ZL114 Aalloy were investigated.The results reveal that the oxidation inclusions or the oxide bifilms in the melt are related with the nucleation of shrinkage

while the solidification mode of melt affects the growth of shrinkage.For Sr-modified melt

because of more oxidation inclusions or oxide films engulfed in the melt and characteristics of gypsum mold and alloy inherent behavior（easy to form paste solidification）

pressure solidification is difficult to eliminate porosity defects

so the cleaning treatment of aluminum liquid is particularly critical.For the unmodified melt

due to the reduction of the modifying process of the melt

the less oxidation inclusions or oxide films in the melt and characteristics of alloy inherent behavior（easy to form progressive solidification）

the shrinkage defects in the samples are decreased significantly.However

because of the influence of acicular eutectic Si

the mechanical properties of the specimen need to be improved.