UCL researchers led by Prof. Peter D. Lee, Prof. Chu Lun Alex Leung, and Dr. Da Guo have developed a bespoke hypereutectic aluminum alloy specifically engineered for Directed Energy Deposition (DED) additive manufacturing. The material, composed of aluminum, nickel, cerium, manganese, and iron, features a grain size under 5 micrometers and a freezing range of 2.8 degrees Celsius. In comparative testing against the industry standard AlSi10Mg, the new alloy demonstrated a 70% increase in yield strength, 50% higher ultimate tensile strength, and residual stress levels below 32 megapascals. The research team utilized synchrotron X-rays and infrared imaging to validate these mechanical properties and thermal behavior during the fabrication process.

Most aluminum alloys currently utilized in DED were originally formulated for conventional casting, which leads to significant cracking and structural defects when subjected to the rapid thermal cycles of laser-based additive manufacturing. By engineering an alloy with a narrow freezing range, the UCL team addresses the primary cause of solidification cracking in high-strength aluminum components. This development is significant for the aerospace and automotive sectors, where high-performance aluminum parts are essential for weight reduction but have historically been difficult to produce via DED. The ability to print crack-free, high-strength aluminum directly impacts the viability of large-scale metal additive manufacturing for structural end-use applications.

This alloy demonstrates that material science must precede process optimization to overcome the inherent limitations of DED for high-performance metals. Commercial adoption will depend on the scalability of the alloy production and its compatibility with standard DED hardware platforms currently used in industrial settings. Users should prioritize evaluating the powder flowability and laser absorption characteristics of this specific composition before integrating it into existing production workflows.