A Cluster Theory Approach To Finding Amorphous Alloy In Ni-based Systems And Study On Coating Produced By Laser Cladding

In this paper, three criterias for selecting clusters were used to select cluster structuresformed by Ni-Zr and Ni-Ta binary crystals, and the selected cluster structures, with cluster linecriterion, electronic concentration criterion and atomic size criterion, were applied into designingNi-based amorphous components. The design of the Ni₅₂Zr₂₅Ta₂₃and Ni_60.5Zr_19.63Nb_18.07Al_1.8alloy components were presented on45steel substrate, so as to get completely amorphouscoating under different output powers of laser cladding. Then coating’s phase and microstructurewere analyzed, and the mechanical properties and corrosion resistance were studied. Resultsshow that: The Ni₅₂Zr₂₅Ta₂₃and Ni_60.5Zr_19.63Nb_18.07Al_1.8alloy components designed by the newcriterion have strong glass-forming ability, what reflected in the X-ray spectrum is a wide rangeof flood scattering peak. Virtually the coatings not only contain anticipatory amorphous phase,but also have cellular crystal and branches. The phase structures are ZrO₂, Al₂O₃andintermetallic compounds of Ni2Ta, Ni3Zr and Ni8Nb. The mechanical properties and corrosionresistant performances of the two kinds of alloy components coating are far superior to thematrix. Balanced the two components’ performances, Ni₅₂Zr₂₅Ta₂₃alloy coating’s mechanicperformance is better, and Ni_60.5Zr_19.63Nb_18.07Al_1.8alloy coating’s corrosion resistantperformance is better. Data show that: the best wear resistance of the Ni₅₂Zr₂₅Ta₂₃alloycomponent coating is0.57mg·mm^-2; The surface hardness of Ni_60.5Zr_19.63Nb_18.07Al_1.8alloycomponent coating is up to2954.3HK, and is with good acid resistance, while the minimum ofinitiating passivation current density is3.0524mA·mm^-2, its weight increase is16.53mg·mm^-2,and is with the best salt tolerance. The amorphous is formed beneficially when Laser poweroutput is3300W with scanning speed2mm/s.