Fatigue-resistant 3D-printed aluminium alloys
A collaboration between the City University of Hong Kong and Shanghai Jiao Tong University created a fatigue-resistant aluminum alloy by using additive manufacturing to create a dual-phase cellular microstructure.
The microstructure boosts fatigue resistance by a factor of about two compared with other aluminum alloys made by additive manufacturing. The dual-phase cellular microstructure helps to confine damage by acting as a dislocation barrier and represents a more general strategy for other alloys. The 3D-printed alloy has been tested in prototypes including aircraft engine fan blades.
“The three-dimensional network of nano eutectic silicon generated by additive manufacturing inside the alloy due to rapid solidification could block the movement of dislocations thus suppressing fatigue crack initiation,” said Professor Lu Jian of CityU who co-led the project, “With controlled defects through process optimisation, the fatigue limit of the bulk NTD-Al alloy is superior to that of all existing Al alloys.”
The findings were published in Nature Materials and also covered in Science as a research highlight. Professor Lu is the recipient of a grant under the CAS Croucher Funding Scheme.