Salehi, M., Kuah, K. X., Huang, Z., Blackwood, D. J., Zhang, S. X., Seet, H. L., & Nai, M. L. S. (2023). Enhancing densification in binder jet additive manufacturing of magnesium via nanoparticles as sintering aids. Journal of Manufacturing Processes, 99, 705–717. https://doi.org/10.1016/j.jmapro.2023.05.096
Abstract:
Additive manufacturing technologies for magnesium alloys have been developing faster than before, but many challenges are on the horizon. The native oxide film covering each Mg powder particle remains a significant challenge to overcome for further advancing sinter-based AM of Mg alloys. The present study investigated if, and how, adding calcium-containing sintering aids can push the sintering boundaries of binder-jet printed Mg powder towards a faster densification rate. Calcium-containing nanoparticles were mixed with Mg-Znsingle bondZr powder to prepare feedstock for binder jetting and sintering. The as-printed and as-sintered samples were investigated using various characterization methods, including scanning electron microscopy, vibrational spectroscopy, density measurement, chemical analysis, and mechanical tests. The results showed that adding the sintering aid to Mg powder improved its densification rate by up to 25 %. Compared to the monolithic Mg counterpart, the physical and mechanical properties of the Mg-0.2 wt% Ca sample increased (i.e., the relative density ∼7 %, tensile strength ∼30 %, compressive strength ∼15 %, elastic modulus ∼18 %, and elongation ∼185 %). These improvements are discussed in the context of consumption mechanisms of calcium interacting with the Mg powder, its MgO film, and the other alloying elements. The current study has taken the first step towards developing a targeted nano-alloying approach to enhance the printing and post-printing processes for Mg alloys fabricated by binder jetting and fused filament fabrication.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the A*STAR - Structural and Metal Alloys Programme (SMAP): Work Package II
Grant Reference no. : A18B1b0061