New aluminium alloy powder boosts DED Additive Manufacturing
Researchers from University College London, Brunel University London, Research Complex at Harwell, University of Bristol, Diamond Light Source, and Oxford Brookes University have partnered to publish research in International Journal of Extreme Manufacturing detailing the behaviour of a high-performance Al alloy during Directed Energy Deposition (DED) Additive Manufacturing.
The study investigated the development of a bespoke aluminium alloy powder designed specifically for DED, addressing longstanding limitations in alloy availability for the process. While DED offers capabilities for fabricating, repairing, and joining near-net-shape components for sectors including biomedical, energy, and transport, the researchers noted that wider adoption has been restricted by the difficulty of processing conventional alloys without defects that degrade mechanical performance.
The feedstock powder was produced by Amazemet, based in Warsaw, Poland, through ultrasonic atomization based on Al–Ni–Ce–Mn–Fe alloy. The team achieved an ultra-fine microstructure with sub-grain sizes below 5 μm and a uniform distribution of intermetallic phases. The alloy also exhibited low residual stress levels of less than 32 MPa and improved mechanical performance in the as-built condition.
When compared to the commonly used AlSi10Mg alloy processed under equivalent DED Additive Manufacturing conditions, the paper reported that the new material demonstrated a 70% increase in yield strength and a 50% increase in ultimate tensile strength. These improvements are attributed to a combination of dispersion strengthening from fine intermetallic phases, grain refinement, and lamellar strengthening mechanisms.
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To better understand the relationship between process conditions and material behaviour, the team developed a multimodal characterisation approach combining in situ X-ray imaging, X-ray diffraction, and infrared imaging. This enabled real-time analysis of thermal behaviour during deposition, including phase evolution, temperature distribution, and stress development.
The study reported that the alloy’s reduced freezing range of 2.8°C and lower solidification contraction contribute to minimising residual stress during and after deposition. Experimentally measured residual stresses remained below 32 MPa, corresponding to less than 16% of the material’s yield strength, in both tensile and compressive regions. According to the researchers, these low stress levels are expected to reduce susceptibility to cracking and distortion, which are common challenges in DED processing of aluminium alloys.
‘Mechanical and in situ thermal-related behaviour during directed energy deposition Additive Manufacturing of a high-performance Al alloy’ is available here.
