Binder Jetting 3D Printing of Magnesium Oxychloride Cement-Based Materials: Parametric Analysis of Manufacturing Factors

Abstract

Powder-bed binder jet 3D printing is a flexible method for producing magnesium oxychloride (MOC)-based articles. Despite the great potential of this additive manufacturing technology for producing free-form MOC cement-based components, the influence of processing factors on final material performance has not yet been investigated and no general models exist for the selection of proper parameters with the desired quality. In the present work, the effect of six key manufacturing factors on the modulus of rupture of MOC cement-based components was studied, using an analysis of variance. The parametric analysis revealed that the material’s strength was strongly influenced by three process inputs: particle size, the amount of binder, and layer thickness. The amount of binder was determined by the “rate of voxel” and the “powder-bed density” and required precise control during the printing process. The introduced quadratic regression model can assist operators in selecting a combination of binder jet process inputs to achieve predetermined final material performance.

Effect of printing strategies on the properties of product in selective Sorel cement activation

“…The effect of “velocity of powder spread” factor can be analyzed as to its impact on the “powder bed density” (ρ pb ) and, according to the previous studies (Salari et al , 2022) while using the current 3D printer machine, this factor increases vibration in the deposition system, where slightly better compaction was achieved for higher spreading velocities. Statistical analysis did not show significancy for this factor on density.…”

“…The process for forming a single line primitive (r V ) was reported at the beginning of this section. For samples printed at high liquid pressure, cement distribution within Z-direction is not homogeneous; macro voids were observed on top of each layer due to crater formation mechanisms and rearranging of particles, while at the bottom of each layer, more volume of cementitious bonds are created (Figure 7) (Lowke et al , 2020; Salari et al , 2022). Additionally, while increasing pressure pushed activator solution into the powder bed, non-reacted MgO was seen on top of a single layer (Figure 7).…”

“…Each r V is made up of aggregate and a portion of cement reactant (a mixture of Poraver aggregates and MgO). The measurement of the powder bed density is a prerequisite step for determining the mass of MgO in a r V and the details of the measurement technique are described in (Salari et al, 2022). Due to the fact that a portion of the cement reactants (MgO) is in the r V and another portion in the activator solution liquid (MgCl 2 ), the corresponding quantity of fluid for each r V can be calculated as:…”

“…Each r V is made up of aggregate and a portion of cement reactant (a mixture of Poraver aggregates and MgO). The measurement of the powder bed density is a prerequisite step for determining the mass of MgO in a r V and the details of the measurement technique are described in (Salari et al , 2022).…”

“…Raster angle, also referred to as printing direction (PD), is the angle between the printhead’s trajectory and the X-direction of the building platform (Shakor et al , 2021; Wu et al , 2017). The material selection is not a parameter for the slicer, but the powder bed density is required to be determined in order to calculate the flow rate (Salari et al , 2022). Eventually, based on the inputs mentioned above, the necessary commands for the 3D printer are generated.…”