Powder Metallurgy Processing Of Nickel Aluminium Bronze Alloys: Microstructural Insights And Performance Evaluation

Nickel aluminium bronze alloys (NAB) are widely used in the manufacture of marine industry components due to their exceptional combination of high mechanical strength and corrosion resistance in seawater.In this study two powder metallurgy processing techniques are investigated: press and sintering (PM), and HIP of encapsulated powder (PM-HIP), to obtain NAB alloys with nominal composition Cu-10Al-5Ni-4Fe-1Mn (wt.%). The influence of processing conditions on densification during sintering and HIPping was examined, along with the effects of subsequent heat treatments on the resulting microstructure and mechanical properties. Comprehensive microstructural characterization was conducted using OM, SEM, electron backscatter diffraction (EBSD) and X-ray diffraction. The mechanical behaviour was evaluated through Charpy impact and tensile tests. Additionally, the corrosion and erosion-corrosion resistance of NAB alloys was analysed. The results demonstrate that the appropriate selection of processing conditions yield fully dense NAB alloys with enhanced mechanical properties and erosion-corrosion resistance compared to conventionally cast NABs.