Impact of heat treatment on microstructure and mechanical properties of additively manufactured aluminum bronze

Journal of Alloys and Compounds. 2026. No. 1074. Article 189162.

Filippova A. V., Yurchenko N. Y., Smirnov S. A., Firsov D. G., Dubinin O. N., Podobrazhnykh A. D., Fedorov F. S., Sybachin A. V., Zhdanov V., Simonov A. P., Narayan R. L., Evlashin S. A.

This study investigates the effects of post-processing heat treatment at 300–500 °C on the microstructure, hardness, and tensile properties of laser powder bed fusion (PBF-LB) processed Al-bronze processed with energy densities (ED) in the range of 125–938 J/mm3. In the as-printed state, sharp needle-like α + β′ laths form at lower ED whereas with increasing ED, the β′ phase progressively dissolves, and the laths become more rounded. Heat treatment caused limited lath coarsening but led to texture randomization and a transition of the phase constitution of the α lath from that containing Al-rich precipitates to Cu-rich precipitates with increasing heat treatment temperature. Heat treatment at 300–400 °C caused embrittlement, whereas treatment at 500 °C improved the strength and ductility of samples, particularly for those processed at ED > 313 J/mm3. The Al-bronze processed at 938 J/mm3 has the best combination of tensile strength (790 MPa) and ductility (0.180 mm/mm) in its as-printed and 500 °C heat-treated state. Finally, the sensitivity of mechanical properties variations with changes in ED and heat treatment temperature are discussed in the context of defect and phase evolution in PBF-LB processed Al-bronze.

Keywords: Mechanical properties, Механические свойства, термическая обработка, heat treatment, микроструктура, microstructure, Laser powder bed fusion, селективное лазерное сплавление