On The Mechanical Performances Of Modified 2024 Alloy Produced By LP: Effect Thermal Treatments

Laser Powder Bed Fusion (LPBF) of high performance aluminium alloys is complicated by their tendency to form hot cracks. Recent developments using inoculants have enabled grain refinement, allowing the production of crack-free parts, though with microstructures distinct from those of traditionally processed materials. This study analyses the microstructure and mechanical behaviour of a high-strength AA2024 aluminium matrix composite, modified with titanium and ceramic particles and fabricated via LPBF. The resulting components showed no solidification defects and reached a matrix hardness of 136.7 HV. Several heat treatment strategies were evaluated, including standard T6 and T5 as well as alternative approaches. These treatments affected the distribution and morphology of key precipitates (S phase, θ phase, Al3Ti). T6 sample hardness was similar to the as-built condition (139.5 HV), while high-temperature aging reduced performance (122.9 HV). In contrast, low-temperature aging and a three-step treatment led to increases in hardness (157.9 HV and 154 HV, respectively).