SPS反应烧结HfB2复合材料的工艺和性能研究

Preparation and Properties of HfB2-ZrSi2-SiC Composites Fabricated by Reactive Spark Plasma Sintering

摘要:

本文针对HfB2陶瓷材料难烧结和韧性差等问题,选择ZrC粉、Si粉和C粉为烧结助剂,借助ZrC-Si-C间的原位反应生成ZrSi2和SiC,促进HfB2陶瓷的烧结,并提高HfB2陶瓷的综合力学性能。HfB2与烧结助剂的混合粉体经放电等离子烧结(SPS)在1600 ℃保温10 min和40 MPa的压力条件下制备出相对密度为96.61%的HfB2-ZrSi2-SiC复合材料,所制样品的硬度、抗弯强度和断裂韧性均随着烧结助剂ZrC-Si-C含量的增加呈现先上升后降低的趋势。当ZrC-Si-C添加量为10 wt.%时所制备样品的综合力学性能最好,其硬度值为26.80±1.2 GPa、抗弯强度为504±40 MPa、断裂韧性值为4.66±0.21 MPa.m1/2。

Abstract:

ZrC, Si and C powders were used as the sintering aids to enhance the densification and the mechanical properties of HfB2, due to the in-situ reaction between ZrC-Si-C at sintering temperature. Dense HfB2-ZrSi2-SiC ceramic composites have been fabricated by reactive spark plasma sintering at 1600 ℃ for 10 min under a pressure of 40 MPa. With the amount of ZrC-Si-C increasing, the Vickers hardness, the flexural strength and fracture toughness of the sintered samples increased first, then decreased. HfB2-10wt.% ZrC-Si-C composites showed the the best comprehensive mechanical properties. The Vickers hardness, flexural strength and fracture toughness of HfB2-10wt.% ZrC-Si-C composites were 26.80±1.2 GPa, 504±40 MPa and 4.66±0.21 MPa.m1/2, respectively.