The modeling and mechanical properties prediction of whisker-reinforced ceramic composites

Whiskers have been extensively used in ceramics as excellent reinforcing phases during the past decades. Despite in-depth investigation of whisker-reinforced ceramics (WRC), however, the time-consuming, environmentally unfriendly, content design blindness of experimental method as well as pathogenicity of whiskers force people to explore quick and green research approaches. Therefore, this work aims at developing a modeling approach of WRC and predicting the mechanical properties of WRC, thereby compensating for the disadvantages of traditional experimental method. Initially, a modeling approach of WRC based on Voronoi tessellation was presented. Then, taking β-Si₃N_4w and Si₃N₄ as research objects, the prediction models of mechanical properties of 0–6 wt% β-Si₃N_4w-reinforced Si₃N₄ ceramics (SWRSC) were established. Finally, the effect of β-Si₃N_4w content on mechanical properties of Si₃N₄-based ceramics was discussed, and the enhancement mechanism of β-Si₃N_4w was revealed. Results indicated that the flexural strength of SWRSC was significantly advanced with increasing β-Si₃N_4w content. Crack deflection and intergranular fracture induced by β-Si₃N_4w as well as load-bearing effect of β-Si₃N_4w were the mainly responsible for the reinforcement of Si₃N₄-based ceramics. The enhancement mechanisms, previously observed experimentally, were effectively simulated. The fracture toughness reached a maximum of 6.17 MPa m^1/2 when β-Si₃N_4w amount was 1 wt%, which was approximately 36.50% higher than monolithic Si₃N₄ ceramic. The predicted value of β-Si₃N_4w optimal content was consistent with relevant experimental conclusions. When β-Si₃N_4w content was 3 wt%, the hardness of Si₃N₄-based ceramics reached the maximum value of 23.21 GPa. The effectiveness of prediction results and the presented modeling method were confirmed by comparing with related test values.