An alloy solidification experiment conducted on Shenzhou spacecraft

To gain a better understanding of how gravity-driven phenomena affect the solidification and crystal growth of metallic materials, directional solidification experiments have been performed on an Al-Al3Ni eutectic alloy and an Al-Bi monotectic alloy on board the unmanned Chinese Shenzhou III spacecraft during its flight. For sake of comparison, identical experiments were also performed in the laboratory on earth. The results of investigations applying metallographic, SEM, EPMA and image analysis techniques are reported. Some interesting differences between the samples solidified in space and their counterparts solidified on the ground are described.