Intensive processing optimization of Zn-Cu fabricated by laser powder-bed fusion

Laser powder-bed fusion (LPBF) of Zn-0.8Cu (wt.%) alloys exhibits significant advantages in the customization of biodegradable bone implants. However, the formability of LPBFed Zn alloy is not sufficient due to the spheroidization during the interaction of powder and laser beam, of which the mechanism is still not well understood. In this study, the evolution of morphology and grain structure of the LPBFed Zn-Cu alloy was investigated based on singletrack deposition experiments. As the scanning speed increases, the grain structure of a single track of Zn-Cu alloy gradually refines, but the formability deteriorates, leading to the defect’s formation in the subsequent fabrication. The Zn-Cu alloys fabricated by optimum processing parameters exhibit a tensile strength of 157 MPa, yield strength of 106 MPa and elongation of 14.7%. This work provides a comprehensive understanding of the processing optimization of Zn-Cu alloy, achieving LPBFed Zn-Cu alloy with high density and excellent mechanical properties.