NUCLEATION MECHANISM OF 8090 Al-Li ALLOY WELD METAL
8090Al—Li合金焊缝金属形核机制

A kind of very fine equiaxed non- dendrite, besides the equiaxed dendrites and the columnar dendrites, exists in the 8090 aluminum-lithium alloy welds. The equiaxed non-dendrites are mainly distributed at the edge of the fusion zone; occasionally they can appear in the intermediate section of weld in the form of banding. The nuclei of equiaxed dendrites and columnar dendrites are the equilibrium tetragonal Al_3Zr particles, while the nuclei of equiaxed non -dendrite are demonstrated to be metastable cubic Al_3Zr particles.