Pressureless sintering of composites consisting of AlN powder and conductive refractory additives was studied using yttrium oxide as a sintering aid. Samples of aluminum nitride-titanium nitride (AlN-25 wt% TiN), aluminum nitride-titanium carbide (AlN-20 wt% TiC), aluminum nitride-titanium diboride (AlN- 20 wt% TiB{sub}2) were prepared by pressureless sintering of the composite green bodies at 1800-1900 ℃ in nitrogen for 1-2 hours. The host dielectric matrix of the composite samples is an AlN ceramic phase containing particles of the conductive refractory compounds. The AlN ceramic matrix reveals high thermal conductivity (137 W/(m-K)), low dielectric constant (7.7) and dielectric loss (0.021) at 3.23 GHz. The AlN-based composites containing TiN, TiC, and TiB{sub}2 possess a lower thermal conductivity (73-87 W/(m-K)) and a higher Vickers hardness (HV= 10.5-12.6 GPa) as compared to the host matrix (137 W/(m-K) and 9.5 GPa, respectively). The dielectric constants of the AlN-(TiN, TiC, TiB{sub}2) composites were measured to be in the range from 9.8 to 23.7. The AlN-25 wt% TiN composite has the highest dielectric constant (23.7) at 3.0 GHz. The microwave properties of the AlN ceramics and the AlN-TiN, AlN-TiC and AlN- TiB2 composites change only slightly in the 3-37 GHz frequency region.
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机译：以氧化钇为烧结助剂，研究了由AlN粉和导电耐火添加剂组成的复合材料的无压烧结。氮化铝-氮化钛（AlN-25 wt％TiN），氮化铝-碳化钛（AlN-20 wt％TiC），氮化铝-二硼化钛（AlN-20 wt％TiB {sub} 2）的样品制备如下：在氮气中1800-1900℃无压烧结复合生坯1-2小时。复合样品的主体介电基质是含有导电耐火化合物颗粒的AlN陶瓷相。 AlN陶瓷基体在3.23 GHz处显示出高导热率（137 W /（m-K）），低介电常数（7.7）和介电损耗（0.021）。与主体基质相比，含有TiN，TiC和TiB {sub} 2的AlN基复合材料具有较低的热导率（73-87 W /（mK））和较高的维氏硬度（HV = 10.5-12.6 GPa） （分别为137 W /（mK）和9.5 GPa）。 AlN-（TiN，TiC，TiB {sub} 2）复合材料的介电常数测得为9.8至23.7。 AlN-25 wt％TiN复合材料在3.0 GHz时具有最高的介电常数（23.7）。 AlN陶瓷以及AlN-TiN，AlN-TiC和AlN-TiB2复合材料的微波特性在3-37 GHz频率范围内只有很小的变化。
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