Toughness describes the ability of a material to resist fracture or crack propagation. It is demonstrated here that fracture toughness of a material can be asymmetric, i.e., the resistance of a medium to a crack propagating from right to left can be significantly different from that to a crack propagating from left to right. Such asymmetry is unknown in natural materials, but we show that it can be built into artificial materials through the proper control of microstructure. This paves the way for control of crack paths and direction, where fracture—when unavoidable—can be guided through predesigned paths to minimize loss of critical components.

中文翻译：

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断裂二极管：断裂韧性的方向不对称

韧性描述了材料抵抗断裂或裂纹扩展的能力。在此证明，材料的断裂韧性可以是不对称的，即，介质对从右向左传播的裂纹的抵抗力与从左向右传播的裂纹的抵抗力可以明显不同。这种不对称在天然材料中是未知的，但是我们证明可以通过适当控制微观结构将其内置于人造材料中。这为控制裂纹路径和方向铺平了道路，在这种情况下，可以通过预先设计的路径引导断裂（在不可避免的情况下），以最大程度地减少关键部件的损失。