Ai Minjun, Song Yuzhu, Long Feixiang, Zhang Yuanpeng, An Ke, Yu Dunji, Chen Yan, Sakai Yuki, Ikeda Masahito, Takahashi Kazuki, Azuma Masaki, Shi Naike, Zhou Chang, Chen Jun
Department of Physical Chemistry, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Adv Sci (Weinh). 2024 Oct;11(40):e2404838. doi: 10.1002/advs.202404838. Epub 2024 Aug 28.
Rapid advancements in electronic devices yield an urgent demand for high-performance electronic packaging materials with high thermal conductivity, low thermal expansion, and great mechanical properties. However, it is a great challenge for current design philosophies to fulfill all the requirements simultaneously. Here, an effective strategy is proposed for significantly promoting the thermal conductivity and machinability of negative thermal expansion alloy (Zr,Nb)Fe through eutectic precipitation of copper networks. The eutectic dual-phase alloy exhibits an isotropic chips-matched thermal expansion coefficient and a thermal conductivity enhancement exceeding 200% compared with (Zr,Nb)Fe, along with an ultimate compressive strength of 550 MPa. The addition of copper reorganizes the composition of (Zr,Nb)Fe, which smooths the magnetic transition and shifts it toward higher temperature, resulting in linear low thermal expansion in a wide temperature range. The highly fine eutectic copper lamellae construct high thermal conductivity networks within (Zr,Nb)Fe, serving as highways for heat transfer electrons and phonons. The in situ forming of eutectic copper lamellae also facilitates the mechanical properties by enhancing interfacial bonding and bearing additional stress after yielding of (Zr,Nb)Fe. This work provides a novel strategy for promoting thermal conductivity and mechanical properties of negative thermal expansion alloys via eutectic precipitation of copper networks.
电子设备的快速发展产生了对具有高导热性、低热膨胀性和优异机械性能的高性能电子封装材料的迫切需求。然而，对于当前的设计理念来说，同时满足所有这些要求是一项巨大的挑战。在此，提出了一种有效的策略，通过铜网络的共晶沉淀来显著提高负热膨胀合金（Zr，Nb）Fe的导热性和可加工性。与（Zr，Nb）Fe相比，该共晶双相合金表现出各向同性的芯片匹配热膨胀系数，导热性提高超过200%，同时具有550 MPa的极限抗压强度。铜的添加重新组织了（Zr，Nb）Fe的成分，使磁转变变得平滑并将其向更高温度移动，从而在宽温度范围内实现线性低热膨胀。高度精细的共晶铜薄片在（Zr，Nb）Fe内构建了高导热性网络，作为热传递电子和声子的通道。共晶铜薄片的原位形成还通过增强界面结合以及在（Zr，Nb）Fe屈服后承受额外应力来促进机械性能。这项工作为通过铜网络的共晶沉淀来提高负热膨胀合金的导热性和机械性能提供了一种新策略。
