Tue, 08 April, 2025
A new paper, co-written by experts from TWI has been published in the journal of Materials Science and Engineering.
The paper, ‘Development of a Novel Heat Treatment in L-PBF Fabricated High Strength A205 Al Alloy: Impact on Microstructure-Mechanical Properties,’ was authored by NSIRC and University of Birmingham PhD student, Francesco Careri with input from TWI Consultant Raja Khan and Talal Alshammari and Moataz M. Attallah from the University of Birmingham’s School of Metallurgy and Materials.
Advances in the additive manufacturing of high-strength aluminium alloys have allowed them to begin replacing the use of cast components for the aerospace and automotive industries. Despite this, there are still challenges around the lack of standardised heat treatments (HT) for the optimisation of mechanical properties.
This paper investigates the development of a novel rapid HT and how it influences both the microstructure and mechanical properties of A205 aluminium alloy (A20X™) which has been fabricated by Laser-Powder Bed Fusion (L-PBF).
Three different HTs were investigated for this research; standard T7 HT, commercial HT, and the newly developed rapid HT. Each of these methods were tested with microstructural analysis using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results revealed that commercial and rapid HT showed a finer grain size (2.4 μm and 2.3 μm, respectively) compared to the standard T7 HT (3.2 μm).
STEM analysis revealed a higher volume fraction and finer Ω-AlCuAgMg and ϑ’-Al2Cu precipitates in the rapid HT compared to the other HTs, while mechanical tests highlighted superior performance for the rapid HT, which achieved a UTS of 465 MPa, compared to the values for standard T7 HT (422 MPa) and commercial HT (449 MPa). In addition, the paper shows how rapid HT showed an increase in fatigue and creep life compared to standard T7 HT and commercial HT.
These findings highlight the ability of rapid HT to refine microstructure and enhance mechanical properties beyond conventional HTs, paving the way for more efficient and sustainable HT strategies for L-PBF manufactured high-strength Al alloys.
This paper is another example of how research being conducted at TWI is progressing parts manufacture for industry.
You can see the paper in full, here:
https://doi.org/10.1016/j.msea.2025.148278