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yexuqing木虫之王 (文学泰斗)
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Ceramic-like strength and metallic toughness in a bulk metallic glass
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Ceramic-like strength and metallic toughness in a bulk metallic glass 兼具类陶瓷强度与金属型韧性的块体金属玻璃 ▲ 作者：Zhengqing Cai, Shidong Feng, Zhen-Qiang Song et al. ▲ 链接： https://www.nature.com/articles/s41586-026-10430-w ▲ 摘要： 金属与陶瓷各有其固有的局限性——金属强度较低且高温稳定性差，而陶瓷则天生脆性。寻找兼具高强度、高断裂韧性与热稳定性的材料仍然是一个重要的科学目标。研究者展示了一种Re–Co–Ta–B块体金属玻璃，它克服了这一基本局限，实现了约6.43 GPa的卓越断裂强度，同时保持约30 MPa·m^{1/2}的断裂韧性。这一强度值超过了此前报道的块体金属玻璃和晶态金属，接近先进陶瓷的强度，同时在韧性方面远超后者。该合金表现出显著的热软化抵抗能力和恶劣环境耐受性，在900 K下仍能保持4.4 GPa的强度，且氧化和腐蚀极轻微。 同步辐射测量和像差校正显微分析揭示了这些性能的起源：一种独特的非晶结构，其继承了Re?B?金属间化合物相的高度类晶体的短程有序结构。第一性原理计算表明，这个原子骨架通过嵌入金属基质中的定向Re–B共价键得到强化，从而在陶瓷键合与金属键合之间架起了桥梁。该研究提出的结构遗传性可作为设计具有前所未有性能组合的下一代非晶材料的指导原则。 ▲ Abstract： Metals and ceramics have contrasting limitations—metals exhibit lower strength and poor high-temperature stability, whereas ceramics are inherently brittle. Materials combining high strength, fracture toughness and thermal stability remain an important scientific objective. Here we report Re–Co–Ta–B bulk metallic glasses (BMGs) that overcome this fundamental limitation, achieving a remarkable fracture strength of about 6.43?GPa while maintaining around 30?MPa?m1/2 fracture toughness. This strength value exceeds previously reported values for BMGs and crystalline metals and approaches the strength of advanced ceramics while far exceeding them in toughness. These alloys exhibit pronounced resistance to thermal softening and harsh environments, retaining a strength of 4.4?GPa at 900?K with negligible oxidation and corrosion. Synchrotron measurements and aberration-corrected microscopy reveal the origin of these properties: a unique amorphous structure that inherits a high degree of crystal-like short-range order from the Re7B3 intermetallic phase. First-principles calculations indicate that this atomic framework is strengthened by directional Re–B covalent bonds embedded in a metallic matrix, thereby bridging the ceramic and metallic bonding. This work suggests structural heredity as a guiding principle for engineering next-generation amorphous materials with previously unattainable property combinations. |
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