Laser-Additive Repair of Cast Ni-Al-Bronze Components

To emulate the refurbishment of service-damaged cast nickel aluminum bronze (NAB) components, a laser-additive repair process using NAB powder feed was developed. Process parameters were first optimized using Taguchi experimental design based on the lowest dilution ratio criterion. The dilution ratio was obtained from single weld beads deposited on flat substrates. Using the optimum process window developed on the flat substrates, the process parameters were further modified to deposit multiple weld beads in a grooved substrate, which was used to emulate remanufacturing of a service-damaged surface condition. Using the optimum laser-additive repair process developed, sound deposits with no cracks but some micropores at acceptable levels for the application, were successfully manufactured. The microstructure and microindentation hardness of the deposited specimen were evaluated in the as-deposited condition.