Fabrication of SiC-Al composites using binder jetting 3D printing and infiltration: effects of printed sample density on infiltration

This study examines how powder bed compaction during binder jetting 3D printing of silicon carbide (SiC) samples influences SiC sample density and affects subsequent aluminum-magnesium (Al+Mg) infiltration of the printed SiC samples. SiC samples were printed with and without compaction, then cured, depowdered, sintered at 1600 °C, and infiltrated with Al+Mg to produce composite samples. Green samples (printed samples after curing and depowdering) were evaluated for density, sintered samples for density and porosity, and infiltrated samples for density, porosity, infiltration uniformity, penetration depth, and morphology. Results show that the density of green samples printed with powder bed compaction was 6.79% higher than that of green samples printed without compaction; however, this advantage was largely diminished after sintering, resulting in similar final density (≈2.53 g/cm 3 ) and porosity (≈36%) for both groups of samples. However, infiltration behavior of these two groups of samples differed substantially: the samples printed with compaction exhibited greater infiltration area and deeper penetration than the samples printed without compaction. Quantitative image processing analysis revealed that the sample printed with compaction exhibited greater percentage of infiltration area as well as deeper infiltration penetration across measured edges compared with the sample printed without compaction.