Laser multi-
layer cladding experiments we re performed on the preferential crystallography surface (plane normal to the pref erential crystallography orientation) of the DD3 single crystal rod and the dire ctional solidification nickel-base
superalloy rod by using superalloy FGH95 pow der. Cladding layers growing epitaxially from the substrate can be obtained. The cladding layer consists of thin columnar dendritic, the primary arm spacing of which is about 10 μm, and the secondary arm is degenerated. γ ′ deposits are
spherical in the dendritic trunk and cubical in the interdendritic area due to the difference of the local
elements aggregation. The sizes of γ ′ phase are less than 0.1 μm. Composition
segregation of main elements in the claddin g layer are highly alleviated on comparing with that of the substrate. After hea t treatment, the γ ′ deposits become cubic-spherical in the cladding layer and the size of them is more homogeneous in all of the single crystal cladding layers. Composition segregation is alleviated further after heat treatment. Mech anical measurement shows that yield strength acquires 97.9% of that in powder me tallurgic
sample and the plasticity surpasses that in powder metallurgic sample, and the fracture of FGH95 shows plastic fracture.