Diamond/aluminum composites, as a new generation of thermal management materials, are caught in the dilemma between inhibiting the formation of Al4C3 and improving the performance. Herein, we proposed a strategy for nanoscale multi-interface phase structure engineering, utilizing a combination of magnetron sputtering and vacuum heat treatment to obtain diamond particles with nanoscale TiC-Ti layers. Prolonging the vacuum heating time increases the content of TiC, but results in significant differences in the morphology and coverage of TiC formed on the diamond(100) and (111) facets. First-principles calculations reveal that the work of adhesion and C-Ti reaction tendency of diamond(100)/Ti are stronger than those of diamond(111)/Ti, clarifying the difference in interfacial properties between diamond/Ti and diamond/TiC. Diamond-TiC-Ti configuration obtained in advance contributes to fabricating the composite with diamond-TiC-Al(Al3Ti) structure, and the multi-interface phase structure is beneficial to improve the interface bonding, adjust the acoustic mismatch, and inhibit the formation of Al4C3. (800 °C 0.5 h)@Ti-coated diamond(100 μm)/aluminum composite with the multi-interface phase exhibits excellent thermal conductivity(646 W m−1 K−1) and outstanding bending strength(358 MPa), exceeding 90 % of the theoretical prediction of the differential effective medium model. The performance of (800 °C 0.5 h)@Ti-coated diamond/aluminum composite is about 30 % higher than that of traditional Ti-coated diamond/aluminum composite. The TiC layer formed by increasing the heat treatment time is thicker and discontinuous, leading to a decrease in the thermal conductivity of the composite and a weakening effect of Al4C3 inhibition. We clarified the formation mechanism of interface structure related to diamond orientation by multi-scale characterization. Based on the thermal conductivity prediction models, the interface structures corresponding to different diamond orientations were considered, and the predicted values showed good consistency with the experimental results. By interface modification engineering, we overcome the dilemma of introducing modified layer to inhibit Al-C reaction while leading to additional interface thermal resistance, providing insights into the interfacial thermal transport mechanism.

中文翻译：

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通过纳米级多界面相结构工程实现高导热性和强弯曲强度的金刚石/铝复合材料


金刚石/铝复合材料作为新一代热管理材料，陷入了抑制 Al4C3 形成和提高性能之间的两难境地。在此，我们提出了一种纳米级多界面相结构工程策略，利用磁控溅射和真空热处理的组合来获得具有纳米级 TiC-Ti 层的金刚石颗粒。延长真空加热时间会增加 TiC 的含量，但会导致金刚石 （100） 和 （111） 刻面上形成的 TiC 的形态和覆盖率存在显着差异。第一性原理计算表明，金刚石 （100）/Ti 的粘附功和 C-Ti 反应趋势强于金刚石 （111）/Ti，阐明了金刚石/Ti 与金刚石/TiC 界面性能的差异。预先获得的金刚石-TiC-Ti构型有助于制备具有金刚石-TiC-Al（Al3Ti） 结构的复合材料，多界面相结构有利于改善界面结合，调整声学失配，抑制 Al4C3 的形成。（800 °C 0.5 h）@Ti涂层金刚石（100 μm）/多界面相铝复合材料表现出优异的导热性（646 W m-1 K-1）和出色的弯曲强度（358 MPa），超过了差分有效介质模型理论预测的90%。（800 °C 0.5 h）@Ti涂层金刚石/铝复合材料的性能比传统的钛涂层金刚石/铝复合材料高约 30%。增加热处理时间形成的TiC层较厚且不连续，导致复合材料的热导率降低，Al4C3抑制作用减弱。 我们通过多尺度表征阐明了与金刚石取向相关的界面结构的形成机制。基于热导率预测模型，考虑了不同金刚石取向对应的界面结构，预测值与实验结果具有良好的一致性。通过界面改性工程，我们克服了引入改性层以抑制 Al-C 反应，同时导致额外的界面热阻的困境，从而为界面热传输机制提供了见解。