A cost-effective one-step densification process based on bi-directional freeze casting was investigated to produce nacre-like alumina/poly (methyl methacrylate) (PMMA) composites with a unique micro-layered (μL) architecture. This method has the advantage of shorter processing time, as it requires only sintering once instead of twice as in the fabrication of conventional brick-and-mortar (BM) composites via freeze casting. By tuning the processing parameters, composites with different ceramic content and layer thickness were obtained. The resultant mechanical properties of μL composites showed that ceramic content and wall thickness affected mechanical properties significantly. The μL composite with fine ceramic walls (8 μm) and relatively high ceramic fraction (72 vol%) exhibited an exceptional combination of high flexural strength (178 MPa) and fracture toughness (12.5 MPa m^1/2). The μL composites were also compared with the conventional BM composites. Although the fracture behaviour of both composites exhibited similar extrinsic toughening mechanisms, the μL composites with longer ceramic walls displayed superior mechanical properties in terms of strength and fracture toughness in comparison with the BM composites comprising short ceramic walls (i.e. bricks), due to the effectiveness of stress transfer of load-bearing ceramic phase within the composites.

研究了一种基于双向冷冻浇铸的经济高效的一步致密化工艺，以生产具有独特的微层（μL）结构的珍珠母状氧化铝/聚甲基丙烯酸甲酯（PMMA）复合材料。该方法的优点是处理时间更短，因为它只需要烧结一次即可，而不是像传统的通过冷冻浇铸的砖瓦（BM）复合材料制造时那样烧结两次。通过调整工艺参数，获得了不同陶瓷含量和层厚的复合材料。μL复合材料的最终机械性能表明，陶瓷含量和壁厚会显着影响机械性能。^1/2）。还将μL复合材料与常规BM复合材料进行了比较。尽管两种复合材料的断裂行为均表现出相似的外在增韧机制，但与具有短陶瓷壁（即砖）的BM复合材料相比，具有较长陶瓷壁的μL复合材料在强度和断裂韧性方面显示出优异的机械性能。复合材料中承重陶瓷相的应力传递特性