Nickel aluminium bronze (NAB) is a critical metal for naval propulsion systems, but making parts with this material is slow and difficult to produce - particularly in Australia.
A new project led by Charles Darwin University (CDU) aims to overcome this challenge by producing NAB parts using high-speed 3D printing technology and testing their resilience in tropical seawater.
The project recently received funding from the Queensland Defence Sciences Alliance (QDSA) and is a collaboration between CDU, James Cook University (JCU), the Australian Institute of Marine Science (through AIMS' National Sea Simulator in Townsville), and advanced manufacturing company SPEE3D.
NAB is a popular alloy for its strength and toughness, high-wear and good corrosion properties.
It is used extensively in aircraft landing gear bearings, marine propellers (including in submarines), pumps and valves, gears and in non-sparking tools - but despite its popularity, traditional manufacturing of NAB alloys is no longer viable in Australia.
This project will produce NAB parts using SPEE3D's cold spray manufacturing technology (CSM) and then be tested for how the parts behave in seawater.
Lead researcher and CDU Research Professor - Advanced Manufacturing/Engineering Kannnoorpatti Krishnan said this project would address a critical need for reliable, corrosion-resistant materials in propulsion systems for the Australian Defence Force.
"This reduces downtime, strengthens resilience in forward operating bases, and ensures continued operational effectiveness in contested maritime environments.
"The project also secures a strategic advantage by generating new knowledge of material behaviour in Pacific tropical waters, where microbial communities are unique and largely unstudied.
"In terms of sovereign industry capability, the project builds a uniquely Australian supply chain by combining SPEE3D's deployable additive manufacturing platform with academic expertise in materials, chemistry, and marine science."
QDSA Director Stuart Blackwell said the Alliance was proud to support the collaboration between Queensland and the Northern Territory.
"The focus on innovative littoral capabilities is highly relevant to marine applications across northern Australia and beyond," Mr Blackwell said.
"This new approach to manufacturing maritime parts closer to the point of need, in an on-demand environment, represents a step change in the future of logistics and sustainment."
SPEE3D is the only company in the world generating an NAB equivalent with its CSM process.
Co-founder and Chief Technology Officer Steven Camilleri - who is also undertaking a PhD with CDU - said with NAB being a supply-chain risk, SPEE3D's CSM process would be crucial to addressing this advanced manufacturing challenge.
"We see enormous potential for cold spray additive manufacturing to address repair, maintenance and sustainment challenges in Pacific maritime environments," Mr Camilleri said.
"If NAB can be printed with a demonstrated equivalence to qualified cast material, the opportunity is far more than novelty.
"It represents the recovery of a strategically important maritime alloy; one that, when produced using additive manufacturing techniques, means parts will become more readily available through a faster, more local, and more controllable production route."
JCU Distinguished Professor Peter Junk, who is a collaborating investigator, said his university's major contributions to the project will be providing expert advice regarding the rare earth incorporation into the NAB base alloy.
"Our team will assist with using surface techniques to understand the microstructure of the alloys and aged samples after field trials," Professor Junk said.
"We will also work on characterising the corrosion performance of the various NAB alloys under variable simulated seawater conditions, to be conducted at the Australian Institute of Marine Science in their seawater simulator than can modify pH, salinity, temperature and flow."
National Sea Simulator (SeaSim) Director Craig Humphrey said the state-of-the-art experimental systems in the Townsville facility were essential for the success of the testing.
"SeaSim is purpose-built to support complex multifactorial research in a controlled, aquarium-based environment," Mr Humphrey said.
"In this project AIMS' experimentation capabilities at SeaSim are uniquely suited to bringing together the ideas and expertise between all participants across the different sectors of industry, academia, and defence to tackle, what is, a large-scale and shared challenge.
"AIMS' tropical location allows for the testing of these alloys under controlled experimental aquarium conditions in the SeaSim and in nearby coastal waters, providing valuable insights into their performance in simulated and real-world marine environments."
CDU Deputy Vice-Chancellor Research and Community Connection Professor Steve Rogers said this funding was another milestone for the University's collaboration with QDSA since becoming a member in 2024.
"This project is a testament to our world-leading knowledge, our capabilities and our commitment to industry collaboration," Professor Rogers said.
"When we joined as a member of QDSA, we said we'd bring our unique expertise and strategic location to the table. We are doing this and more, proving Australia's most remote university can advance defence innovation, science, and technology capabilities at a national level."
