Munch E, Launey M E, Alsem D H, Saiz E, Tomsia A P, Ritchie R O
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Science. 2008 Dec 5;322(5907):1516-20. doi: 10.1126/science.1164865.
The notion of mimicking natural structures in the synthesis of new structural materials has generated enormous interest but has yielded few practical advances. Natural composites achieve strength and toughness through complex hierarchical designs that are extremely difficult to replicate synthetically. We emulate nature's toughening mechanisms by combining two ordinary compounds, aluminum oxide and polymethyl methacrylate, into ice-templated structures whose toughness can be more than 300 times (in energy terms) that of their constituents. The final product is a bulk hybrid ceramic-based material whose high yield strength and fracture toughness [ approximately 200 megapascals (MPa) and approximately 30 MPa.m(1/2)] represent specific properties comparable to those of aluminum alloys. These model materials can be used to identify the key microstructural features that should guide the synthesis of bio-inspired ceramic-based composites with unique strength and toughness.
在新型结构材料合成中模仿天然结构这一概念引发了极大的兴趣，但实际进展却寥寥无几。天然复合材料通过复杂的分级设计实现强度和韧性，而这种设计极难通过合成来复制。我们通过将两种普通化合物——氧化铝和聚甲基丙烯酸甲酯——组合成冰模板结构来模拟自然的增韧机制，其韧性（从能量角度而言）可比其组分高出300多倍。最终产品是一种块状混合陶瓷基材料，其高屈服强度和断裂韧性[约200兆帕斯卡（MPa）和约30MPa·m(1/2)]代表了与铝合金相当的特定性能。这些模型材料可用于识别关键的微观结构特征，这些特征应指导合成具有独特强度和韧性的仿生陶瓷基复合材料。
