Stereolithography of SiOC Polymer‐Derived Ceramics Filled with SiC Micronwhiskers

Abstract

Due to complicated manufacturing methods and lack of machinability, the use of engineering ceramics is limited by the manufacturing processes used to fabricate parts with intricate geometries. The 3D printing of polymers that can be pyrolyzed into functional ceramics has recently been used to significantly expand the range of geometries that can be manufactured, but large shrinkage during pyrolysis has the potential to lead to cracking. In this work, a method to additively manufacture particle‐reinforced ceramic matrix composites is described. Specifically, stereolithography is used to crosslink a resin comprised of acrylate and vinyl‐functionalized siloxane oligomers with dispersed SiC whiskers. After crosslinking, the part is pyrolyzed to amorphous SiOC while the SiC whiskers remain unaffected. Composite ceramics shrink 37% while unreinforced parts shrink 42%; this significant reduction in shrinkage improves part stability. Importantly, these ceramic matrix composites contain no visible porosity nor cracking on the microstructural level. With the introduction of SiC, hardness increases from 10.8 to 12.1 GPa and density decreases from 2.99 to 2.86 g cm−3. Finally, printed ceramic porous structures, gears, and components for turbine blades are demonstrated. Applying stereolithographic techniques to ceramic matrix composites, this work may improve processing and properties of ceramics for applications that require complex geometries.

Effect of Holding Time During Sintering on Microstructure and Properties of 3D Printed Alumina Ceramics

“…He et al (2018) fabricated zirconia ceramic parts through stereolithographybased 3D printing technology and found that the sintered bodies displayed significant shrinkage of 35.26% after sintering. Brinckmann et al (2018) fabricated SiC-based composite ceramics through stereolithography with shrinkage of 37%. Aduba et al (2017) fabricated β-tricalcium phosphate through stereolithography with shrinkage of 7.14∼12.91% and found that the shrinkage in Z direction was significantly greater than that in the other two build orientations.…”

Additive manufacturing of SiBCN/Si3N4w composites from preceramic polymers by digital light processing

“…However, some ceramic powders (e.g., SiC, SiBCN, ZrC) exhibit a high refractive index, leading to high light refraction and absorption, which signicantly reduces the light-penetration depth in the slurry material and disables the SLA printing process of the ceramic slurry. 14 Polymer-derived ceramic (PDC) routes provide another way of producing these materials. Hence, stereolithography of PDCs could be an effective method for fabricating these ceramics with high refractive indices.…”

“…17,18 Intensive research has been conducted on the 3D printing of PDCs. 5,[14][15][16]19,20 However, the liner shrinkage is relatively high (>25%), which may lead to collapse or some defects of the component.…”

“…[21][22][23] Various llers have been shown to be effective in strengthening PDCs, including carbon nanotubes, ceramic bers, or graphene. 14,24,25 SiBCN ceramics are a popular class of new ceramic materials with high thermal and phase stability. [26][27][28][29] Polyborosilazane (PBSZ), the precursor of SiBCN, is a liquid polymer with a high ceramic yield.…”

3D Printing of Complex‐type SiOC Ceramics Derived From Liquid Photosensitive Resin

“…The basic limitations to produce ceramic materials from cured polymer green body result from the extraordinary high‐volume shrinkage, which causes cracks in the sample. By adding fillers to the resin formulation, such as inert SiC, B 4 C, Si 3 N 4 , or BN powder, the volume shrinkage of the ceramic can be effectively solved according to the filler volume effect . The addition of fillers reduces the release of volatile decomposition materials, resulting in a significant increase in ceramic yield, and can also reduce cracks formation and dimensional changes during the conversion of the polymer to the ceramic.…”