Microstructure control during laser deposition of nickel-based superalloy DS Rene80

Rene 80 has been widely used in aero-engine, gas turbines and other high temperature applications because of its pronounced combination of good corrosion resistance, fatigue resistance and excellent mechanical properties. Laser controlled directional solidification is always considered to be the better way to manufacture and repair hot-section components. The paper focused on the dendrite growing morphology controlling through comprehensive effect of laser deposition parameters and substrate crystallographic orientation. With same parameters elaborately selected, vertical walls were built up by familiar laser beam scanning pattern and different substrate crystallographic orientation, parallel and vertical to the building up direction of vertical wall, respectively. The optical micrographs (OM) and Electron backscatter diffraction (EBSD) investigation were performed mainly on the transverse, longitudinal and vertical cross-section of both vertical walls above mentioned. At the same time the pole figures gave the misorientation angle of the vertical wall with fast identical crystallographic orientation. phase precipitates was investigated of vertical walls by SEM image. The paper reported a route to produce full directional solidified microstructure with different substrate crystallographic orientation.