Microstructure and Properties of Ni3 (Si, Ti) Intermetallic Cladding with Nb Addition
Laser cladding technique was used to form Ni3(Si,Ti) intermetallic coating by Nb addition on Ni-based superalloy substrate. The coating was investigated by optical microscopy and X-ray diffraction (XRD). The clad coating was dense, compact and smooth. An excellent bonding between the coating and the substrate was ensured by a strong metallurgical interface. Ni3(Si,Ti) phase was detected in all of the claddings, and NbNi3, Nb3Ni2Si were detected in Nb additional experiments. The peaks intensity of Nb3Ni2Si and NbNi3 increased with the increasing of Nb content. The Ni3Nb and Nb3Ni2Si were formed when Nb was beyond its solubility in the L12 Ni3(Si,Ti). The average microhardness of the coating was improved with the increasing of the Nb content. The microhardness was up to 530Hv when the atom percentage of Nb addition reached 5%, and it was much greater than that of Ni-based superalloy substrate.
Yu Zhou, Shan-Tung Tu and Xishan Xie
Y. N. Sun et al., "Microstructure and Properties of Ni3 (Si, Ti) Intermetallic Cladding with Nb Addition", Key Engineering Materials, Vols. 353-358, pp. 1716-1719, 2007