AlN-BN复相陶瓷的热等静压制备与性能研究

以氮化铝(AlN)和氮化硼(BN)为原料, 无烧结助剂、热等静压烧结制备了AlN-BN复相陶瓷, 研究了热等静压温度和压强对两种不同原料配比(摩尔比)烧结试样的微观结构和性能的影响。结果表明: 增加BN的添加量对复相陶瓷的烧结致密化影响较小, 但逐渐降低硬度和热导率、增大体积电阻率。相同原料配比下, 复相陶瓷的密度越高, 其热导率、体积电阻率、硬度越高。热导率和体积电阻率的实测值与两相复合模型方程较为符合。当n_AlN:n_BN=75:25时, 在温度为1600℃、压强为90 MPa、保温3 h的热等静压工艺下可以制备出相对密度达98.03%、热导率为77.29 W/(m·K)、体积电阻率为1.35×10¹⁵ Ω·cm的复相陶瓷。

Fabrication and Property of AlN-BN Composites by Hot Isostatic Pressing

AlN-BN composites were fabricated by hot isostatic pressing (HIP) without sintering aid, using aluminum nitride (AlN) and boron nitride (BN) powders as raw materials. The effects of HIP temperature and pressure on microstructure and properties of composites with two different raw material ratios (molar ratio) were investigated. The results show that increasing amount of BN has little impact on densification, but decreases the hardness and thermal conductivity while increases the volume resistivity. The higher the density of the composite is, the higher thermal conductivity, volume resistivity and hardness are. The thermal conductivity and volume resistivity values conform the formula: . AlN-BN composites with the ratio of n_AlN:n_BN = 75:25 were prepared at 1600 ℃, 90 MPa and a dwell time of 3 h by HIP, achieving density of 98.03%, thermal conductivity of 77.29 W/(m·K) and a volume resistivity of 1.35 × 10¹⁵ Ω·cm.