Interface phase evolution during laser cladding of Ni-Cu alloy on nodular cast iron by powder pre-placed method

Nodular cast iron is famous for its poor weldability owing to the great tendency of chilled structure in the interface zone during welding and cladding process. In order to eliminate chilled structure, laser cladding nodular cast iron using powder pre-placed method was successfully carried out. The dilution ratio could reduced obviously, and the chilled structure also could be eliminated. The microstructure was determined and the microhardness characteristics were researched. Optical microscope (OM) and Scanning electron microscopy (SEM) were used to identify the microstructure. Chemical composition was carried out using Energy dispersive spectrometer (EDS). The results also showed that the average microhardness of the interface zone decreased obviously when the chilled structure was eliminated.