Aging responses of an Al-Cu alloy fabricated by selective laser melting

Aging responses of selective laser melted AlCu5MnCdVA alloys were investigated in this work. After artificial aging treatment, the precipitate strengthening makes the greatest contribution to the strength. At a lower aging temperature (426 K), nano-sized precipitates including AlxCuyMnz result in a limited sacrifice of the plasticity but a significant improvement in strength in the early stage. As the aging duration increases. theta '' and theta' precipitates nucleate, which can strongly improve the strength. Samples aged for 48 h have the highest ultimate tensile strength (473 MPa) due to the presence of.' with high aspect ratio and dispersed theta''. At a higher aging temperature (446 K), The mixed theta'' and theta' layer structured precipitates contribute to the mechanical properties of the samples aged for 6 h and 10 h. The precipitate growth and the theta'' to theta' transformation both significantly affect the strength and ductility trade-off. Because the interfacial energy of theta'' is smaller than that of.', the coarsening rate of theta'' is slower. As a result, the in-situ transformed theta' is smaller compared with the.' nucleating at the defects, which is beneficial for the strength increase. The loss of Cd during SLM is one of the main reasons for the inapplicability of the traditional aging methods. The results highlight the importance of controlling the precipitates through post-aging process.

Automated summary

The research on aging responses of selective laser melted AlCu5MnCdVA alloys found that precipitate strengthening makes a significant contribution to the strength. The type and quantity of precipitates formed at different aging temperatures have varying effects on the alloy's strength and ductility. Controlling the formation and evolution of precipitates can improve the mechanical properties of the alloy.