Repair and manufacturing of single crystal Ni-based superalloys components by laser powder deposition—A review

摘要: Laser powder deposition is one of the most promising methods for repairing single crystal Ni-based superalloys components used in hot-section gas turbine engines order to extend their lifetime and reduce overall cost. The microstructure deposited on substrates similar materials depends mainly involved, orientation tracks relation substrate parameters. In present paper these relations are discussed illustrated case multiple layer depositions NiCrAlY Rene N4 (100) SRR99 CMSX-4 superalloys. On other hand, when aging treatment applied directly solidification resulting from laser deposition, abnormal γ/γ′ microstructures may result, due inhomogeneity created by alloying elements partition during solidification. Performing a homogenization annealing before circumvents this difficulty. homogenizing also eliminates undesirable brittle phases microstructure, such as carbides topologically close-packed compounds.