Laser Cladding of Ni-Based Hardfacing Alloy Replacing Stellite06
For the disadvantages of Co element, such as rarity, high price and nuclear pollution, the Co-based materials will be eliminated in the valves which are used in the third and fourth-generation nuclear plants. In this paper, the composition of a Co-free Ni-based alloy was designed. With laser cladding technology, the Ni-based coatings were obtained. Microstructure of the coatings was characterized by optical microscopy (OM) and scanning electron microscopy (SEM). The phases in the surface layer were identified by X-ray diffraction (XRD) and energy-dispersive spectrometer (EDS). And the wear resistance of the coatings were tested and compared with Co-based alloy. The results showed that the coatings were mainly made of dendrite phases and interdendritic constituents. The dendrites were characterized of primary dendrites M7C3 and M23(CB)6 and some Ni3Al round particles uniformly dispersed in the γ-Ni matrix. There were a bit of Ni3B and Ni3Si phases in the coatings. The wear volume loss of Ni-based alloy was close to of Co-based alloy.
Long Chen, Yongkang Zhang, Aixing Feng, Zhenying Xu, Boquan Li and Han Shen
S. Liu et al., "Laser Cladding of Ni-Based Hardfacing Alloy Replacing Stellite06", Key Engineering Materials, Vol. 464, pp. 647-650, 2011