Metal Additive Manufacturing Conference - MAMC 2021

The paper presents a part of an integrated experimental chain to manufacture new advanced biodegradable Mg-based implants from powder raw materials by Selective Laser Melting (SLM). The Mechanical Alloying (MA), as a complex solid-state synthesis procedure, was used for obtaining Mg powder alloys with different compositions in the system Mg-xZn-yZr-zCa: Mg-4Zn-0.8Ca-0.5Zr, Mg-6Zn-0.8Ca-0.5Zr and, Mg-10Zn-0.8Ca-0.5Zr. The targeted scientific objectives were to achieve the quality of the powders which is a determinant factor during additive manufacturing – SLM 3D printing; the quality of the powders affects the processing conditions such as flowability, packing of the powders, nature of heat transfer, layer thickness and surface roughness. Many process variables need to be controlled in order to achieve the desired performance-related properties of powders, suitable for SLM. The morphology, grain size distribution and contamination of the milled powders strongly depend on the process variables in mechanical alloying such as milling time, process control-agent, ball to powder weight ratio, the milling atmosphere, etc. Mechanical alloying experiments were carried out for different milling times and speeds using stainless steel balls and a process control agent (i.e. 3% n-heptane solution) to avoid excessive cold welding between powder particles and to inhibit agglomeration. A complex chemical and structural characterization was performed on the obtained powder alloys.