Dislocation-toughened ceramics.
Dislocation-toughened ceramics.
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DOI：
10.1039/d0mh02033h
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发表时间：
2021-05
影响因子：
13.3
通讯作者：
L. Porz;Arne J. Klomp;X. Fang;Ning Li;C. Yildirim;C. Detlefs;E. Bruder;Marion Höfling;W. Rheinheimer;E. Patterson;P. Gao;K. Durst;A. Nakamura;K. Albe;H. Simons;J. Rödel
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文献类型：
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作者：
L. Porz;Arne J. Klomp;X. Fang;Ning Li;C. Yildirim;C. Detlefs;E. Bruder;Marion Höfling;W. Rheinheimer;E. Patterson;P. Gao;K. Durst;A. Nakamura;K. Albe;H. Simons;J. Rödel
功能和结构陶瓷在无数高科技应用中已成为不可替代的。然而，它们固有的脆性极大地限制了应用范围，并且尽管进行了广泛的研究，但特别是短裂纹难以克服。虽然由移动的位错携带的局部塑性允许金属具有期望的韧性，但人们普遍认为高结合强度会阻碍陶瓷的基于位错的增韧。在这里，我们证明了诱导和工程陶瓷中的位错微观结构，提高裂纹尖端韧性的可能性，即使这样的韧化不会自然发生后，常规处理。借助现代显微镜和模拟技术，我们揭示了在环境温度下成功设计基于位错的韧性的关键因素。对于许多陶瓷，由于某些固有性质（例如结合强度），基于位错的塑性区并非不可能，但受到工程量（即位错密度）的限制。位错密度的影响表现在表面附近的区域，并建议转移到块体陶瓷。新的合成方法在提高陶瓷材料力学性能方面具有意想不到的潜力。
Functional and structural ceramics have become irreplaceable in countless high-tech applications. However, their inherent brittleness tremendously limits the application range and, despite extensive research efforts, particularly short cracks are hard to combat. While local plasticity carried by mobile dislocations allows desirable toughness in metals, high bond strength is widely believed to hinder dislocation-based toughening of ceramics. Here, we demonstrate the possibility to induce and engineer a dislocation microstructure in ceramics that improves the crack tip toughness even though such toughening does not occur naturally after conventional processing. With modern microscopy and simulation techniques, we reveal key ingredients for successful engineering of dislocation-based toughness at ambient temperature. For many ceramics a dislocation-based plastic zone is not impossible due to some intrinsic property (e.g. bond strength) but limited by an engineerable quantity, i.e. the dislocation density. The impact of dislocation density is demonstrated in a surface near region and suggested to be transferrable to bulk ceramics. Unexpected potential in improving mechanical performance of ceramics could be realized with novel synthesis strategies.