Effect of SiC whiskers on the mechanical properties of polymer-derived ceramics prepared by digital light processing and its strengthening and toughening mechanism

The mechanism of SiC whiskers-enhanced polymer-derived ceramics prepared by digital light processing (DLP) was investigated. The results showed that the introduction of SiC whiskers can significantly improve the mechanical properties of SiCO ceramic. When the content of SiC whiskers in the precursor photosensitive resin varied from 0 to 5 wt%, the bending strength of samples increased from 44.2 ± 4.1 MPa to 260.1 ± 49.7 MPa, and the fracture toughness improved from 1.48 ± 0.03 MPa·m 1/2 to 3.23 ± 0.12 MPa·m 1/2 , respectively. The Weibull modulus of the precursor composite ceramics prepared by DLP technology was 10.45. The mechanisms of SiC whisker toughening of SiCO ceramics mainly include fracture and pull-out of the whisker, deflection, bridging of cracks, the directional distribution of whiskers, and compressive stress of the SiC whisker on the ceramic matrix. This work will have important guiding significance for the industrial application of additive manufacturing precursor composite ceramics.