Investigation of a nickel aluminium bronze alloy fabricated by directed energy deposition additive manufacturing

• Main Author: Chiam, Jay-Sen
• Other Authors: Zhou Kun
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/141404
• Institution: Nanyang Technological University

Nickel aluminium bronze (NAB) is a common material used in marine and offshore applications. The potential of the material to achieve high strength and high corrosion resistance make it an attractive material to use in seawater conditions. However, there are many disadvantages to conventional manufacturing methods for NAB. This includes long lead time and unfavourable microstructure due to the slow cooling rate. Additive manufacturing is able to manufacture complex structures additionally, AM is able to overcome these disadvantages with quicker production time as well as altering the microstructure to suit the application. In this paper, directed energy deposition (DED) of Cu-9Al-5Ni-5Fe NAB powder was used to produce single track specimens, and the effects of laser power and printing speed on the properties of the specimens were studied. A process parameter window was established based on the properties of the specimens, and mathematical models were derived to predict the printed geometry. The parameters were optimised to achieve the best print quality that is free of defects. DED-built single tracks displayed superior hardness compared to cast NAB. This work proves that DED is a potential manufacturing method to fabricate NAB components with superior performance to that of conventional manufacturing methods.