The effects of different cooling rates on the microstructure and mechanical properties at different wall thickness locations of the plaster casting ZL205 Aalloy were investigated.The results indicate that the grain size of alloy is obviously refined with the increase of the cooling rate.When the cooling rate is low

the grain size and mechanical properties of the alloy exist gradients at different wall thicknesses

and microstructure and mechanical properties of each part of the alloy can be fairly well-distributed by increasing the cooling rate.When a 30 mm thick cold iron is placed

the average grain size of each part of alloy reach 70μm

and the average tensile strength reaches 389.8 MPa

while the elongation is only 5.4%.