A New Approach for Manufacturing Stochastic Pure Magnesium Foam by Laser Powder Bed Fusion: Fabrication, Geometrical Characteristics, and Compressive Mechanical Properties

Abstract

Herein, stochastic pure magnesium foam using laser powder bed fusion (LPBF) is fabricated and its geometric characteristics and mechanical properties are investigated. As volumetric energy density (VED) increased from 20 to 40 J mm−3 by controlling process parameters, porosity changed to 42.7 and 40.5%, respectively. Furthermore, the average sizes of interior consolidated/pore areas were 154.6 μm/142.9 μm (20 J mm−3 VED) and 230.8 μm/182.2 μm (40 J mm−3 VED), respectively. Magnesium foam induces lack‐of‐fusion defects through variable control of the LPBF process, and as such defects are connected, open pore structures are suggested to be formed. Stochastic pure Mg foam is composed of a main α‐Mg phase and a small amount of MgO phases. Room temperature compression test results obtained compressive yield strengths of 37 MPa (20 J mm−3) and 46 MPa (40 J mm−3). Compared with conventional pure Mg foam with similar relative density, LPBF Mg foam had relatively greater mechanical properties. This is considered to be due to the fine twin‐like microstructure formed by rapid solidification during LPBF. In conclusion, with LPBF, a biocompatible Mg foam with an open pore structure and outstanding mechanical properties was manufactured efficiently.

Pre‐Print‐Prediction of Morphological Properties for Designed Materials Manufactured via Laser‐Based Powder Bed Fusion of Metals on a Multi‐Laser Machine

“…tomography (μCT) is frequently utilized. [9,21,22,[24][25][26] This method can also determine the SR of porous samples. [26] Two Haynes 282 investigations show that DM's morphological properties-relative density (RD), surface ratio (SR), mean pore diameter (PD), and mean strut diameter (SD)-underly determinable tolerance limits and hence are repeatable across different laser units and build jobs.…”

“…[2,3,8,9] Process adaptations-either modifying the powder feedstock, or process and machine parameters-can be used to provoke randomly distributed porosity into PBF-LB/M components. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] For the approach of process parameter adaptions, the formation of pores is driven by the controlled introduction of defects, e.g., lack of fusion. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] In two previous studies so-called designed materials (DMs) were produced from the nickel-based superalloy Haynes 282 -UNS N07208 ).…”

“…[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] For the approach of process parameter adaptions, the formation of pores is driven by the controlled introduction of defects, e.g., lack of fusion. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] In two previous studies so-called designed materials (DMs) were produced from the nickel-based superalloy Haynes 282 -UNS N07208 ). [9,22,26] Their open porosity was fabricated by lowering laser power, increasing scan speed, hatch distance, or layer thickness in comparison to a standard process parameter set.…”

“…[9,22,26] Multiple studies analyzed DM's morphology regarding porosity (or RD), pore, and strut size. [9][10][11][12][13][14][15][16][17]20,21,[23][24][25]27] These investigations focus on process parameter influences and have not assessed the property's scatter. [9][10][11][12][13][14][15][16][17]20,21,[23][24][25]27] Determining the RD (or porosity) by calculating the ratio of dimensions and weight is a commonly used method for porous samples.…”

“…[9][10][11][12][13][14][15][16][17]20,21,[23][24][25]27] These investigations focus on process parameter influences and have not assessed the property's scatter. [9][10][11][12][13][14][15][16][17]20,21,[23][24][25]27] Determining the RD (or porosity) by calculating the ratio of dimensions and weight is a commonly used method for porous samples. [14,16,[20][21][22][23][24]26] For the pore and strut size, the digital assessment via microcomputed…”