B4C-SiC复相陶瓷的制备与性能
Preparation and Properties of B4C-SiC Composite Ceramics
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摘要: 采用粒径为10.22 μm的B4C粉和粒径为1.07 μm的β-SiC粉,通过球磨混合后用真空热压烧结工艺,在1 900~2 100 ℃制备了纯B4C陶瓷和B4C-20%SiC复相陶瓷,并进行了相结构分析和力学性能测试.结果表明:SiC的添加对B4C陶瓷的致密度影响不大,当烧结温度为2 100 ℃时,纯B4C陶瓷和B4C-20%SiC复相陶瓷的相对密度分别为87.9%和87.0%;孔隙率显著地影响B4C基陶瓷的力学性能,抗弯强度σw与孔隙率θ的关系符合公式σw=257exp(-2.18θ).Abstract: Pure B4C and B4C-20%SiC composite ceramics were prepared by hot-pressing sintering technique after ball-mill mixing in the temperature range of 1 900-2 100 ℃,using B4C powder with a particle of 10.22 μm and β-SiC powder of 1.07 μm as the starting materials.Phase structure and mechanical properties had been studied.The results indicate that,SiC addition had little effect on the densification of B4C composites,and the relative densities of pure B4C ceramic and B4C-20%SiC composite were 87.9% and 87.0% respectively at the sintering temperature of 2 100 ℃.Porosity influenced the mechanical properties of B4C based composites greatly,and the relationship between bending strength (σw) and porosity (θ) could be expressed as σw=257exp(-2.18θ).