Laser powder bed fusion of mixed aluminum powders: Microstructure features and mechanical properties

The aluminum alloy was synthesized by the LBBF method from a mixture of different secondary aluminum powders containing Mg, Zn, Fe, Ce, Si, Co and Ni alloying elements with their total amount of about 6 wt%. The annealing treatment of the alloy at 200 degrees C relieved high internal stress, which allowed to achieve an excellent combination of strength and plasticity. Depending on the scanning speed, the tensile strength and relative elongation varied from 266 to 324 MPa and from 16 to 19 %, respectively. Such properties were the result of the ultra-fine cellular microstructure formation, with the cell boundaries formed by chains of nanosized aluminide particles. Detailed studies of the heterogeneity of the microstructure and its morphology were carried out. High thermal stability of the synthesized material was established.