The effect of heat input on the microstructure and properties of nickel aluminum bronze laser clad with a consumable of composition Cu-9.0Al-4.6Ni-3.9Fe-1.2Mn

The effect of heat input in the laser cladding of nickel aluminum bronze was investigated. Nickel aluminum bronze castings were clad with a consumable of the composition Cu-9.0Al-4.6Ni-3.9Fe-1.2Mn and exposed to a variety of heat inputs from 42.5 to 595 J/mm. At the lowest heat input, the deposit microstructure was almost entirely martensitic. Increases in heat input caused the amount of alpha to increase. Depending upon heat input, the alpha was present as grain boundary allotriomorphs, secondary Widmanstatten alpha sideplates, and intragranular Widmanstatten alpha precipitates. The reheated zones were of lower hardness and, at all heat inputs, consisted of a mixture of grain boundary allotriomorphs and Widmannstatten alpha and martensite. Laser cladding improved the corrosion- and cavitation-erosion resistance of the surfaces but reduced their ductility. The properties of the clad surfaces depended on heat input.