Improvement in mechanical properties in AlN-h-BN composites with high thermal conductivity
Improvement in mechanical properties in AlN-h-BN composites with high thermal conductivity
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DOI：
10.1007/s40145-021-0506-0
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发表时间：
2021-09-13
影响因子：
16.9
通讯作者：
Zhou, Ji
中科院分区：
文献类型：
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作者：
Liu, Zetan;Zhao, Shiqiang;Zhou, Ji
改善氮化铝-六方氮化硼(AlN-h-BN)陶瓷的可加工性，同时保持高强度和高导热系数是可能的。以氧化钇(Y2O3)为助烧剂，采用热压烧结法制备了以0~30wt%BN为第二相的复相陶瓷。研究了材料的相组成、密度、显微组织、力学性能、导热性能和介电性能。烧结助剂与原料粉末颗粒表面的氧化物杂质发生反应，有利于净化晶界，提高致密化程度。最佳的BN含量使复相陶瓷的抗弯强度和断裂韧性分别提高了475 Mpa和4.86 Mpa中心m(1/2)。随着BN含量的增加，复合材料的导热系数和硬度逐渐降低，但导热系数的最小值仍为85.6W中心点m(-1)中心点K-1。在22~26 GHz范围内，样品的相对介电常数和介电损耗分别为6.8~8.3和2.4×10~(-3)~6.4×10~(-3)。
It is possible to improve the machinability of aluminum nitride-hexagonal boron nitride (AlN-h-BN) ceramics while maintaining high strength and high thermal conductivity. The composite ceramics with 0-30 wt% BN as secondary phase were prepared by hot pressed sintering, using yttrium oxide (Y2O3) as sintering aid. The phase composition, density, microstructure, mechanical properties, thermal conductivity, and dielectric properties were investigated. The sintering additives were favorable to purify the grain boundaries and improve densification, reacting with oxide impurities on the surface of raw material powder particles. The optimum BN content improved the flexural strength and fracture toughness of composite ceramics with 475 MPa and 4.86 MPa center dot m(1/2), respectively. With increasing the amount of BN, the thermal conductivity and hardness of composites gradually decreased, but the minimum value of thermal conductivity was still 85.6 W center dot m(-1)center dot K-1. The relative dielectric constant and dielectric loss tangent of the samples ranged from 6.8 to 8.3 and from 2.4 x 10(-3) to 6.4 x 10(-3), respectively, in 22-26 GHz.