Heat dissipation material with programmable anisotropic property is very challenging, yet can realize the controllable thermal diffusion for heating device. In this work, anisotropic Si₃N₄ ceramics with oriented grains are prepared to adjust and improve the mechanical and thermal properties under the applied stress field by rolling film forming technology. Through the design of the sintering aids in the process of liquid‐phase sintering, the orientation degree of the Si₃N₄ grains is programmable as well as the mechanical property and the thermal property of the Si₃N₄ ceramics. As a consequence, the obtained Si₃N₄ ceramics show significant anisotropy in mechanical properties and thermal conductivity. The typical fracture toughness and thermal conductivity along the grain orientation direction are 10.6 MPa⋅m^1/2 and 45.45 W/(m⋅K) while they are 4.5 MPa⋅m^1/2 and 66.42 W/(m⋅K) in the direction perpendicular to the oriented grain, respectively. This grain orientation method paves the way for the thermal performance design and the production of programmable heat dissipation material.

中文翻译：

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机械性能和热性能可控的各向异性SI3N4陶瓷的制备策略

具有各向异性的可编程性能的散热材料非常具有挑战性，但是可以实现加热装置的可控热扩散。在这项工作中，通过滚膜形成技术制备了具有取向晶粒的各向异性Si ₃ N ₄陶瓷，以调节和改善施加应力场下的机械和热性能。通过在液相烧结过程中设计烧结助剂，可以对Si ₃ N ₄晶粒的取向度以及Si ₃ N ₄陶瓷的机械性能和热性能进行编程。结果，获得的Si ₃ N ₄陶瓷在机械性能和导热性方面表现出明显的各向异性。沿晶粒取向方向的典型断裂韧性和热导率分别为10.6 MPa·m ^1/2和45.45 W /（m·K），而在晶粒取向方向的典型断裂韧性和导热率分别为4.5 MPa·m ^1/2和66.42 W /（m·K）。垂直于取向晶粒的方向。这种晶粒取向方法为热性能设计和可编程散热材料的生产铺平了道路。