Effects of VC additives on densification and elastic and mechanical properties of hot-pressed ZrB2-SiC composites
Effects of VC additives on densification and elastic and mechanical properties of hot-pressed ZrB2-SiC composites
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DOI：
10.1007/s10853-017-1850-7
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发表时间：
2018-03-01
影响因子：
4.5
通讯作者：
Guo, Shuqi
中科院分区：
文献类型：
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作者：
Guo, Shuqi
在本研究中，添加3~10wt%VC的高密度ZrB2-20体积%碳化硅复合材料是在1750A℃、20 Mpa真空条件下热压1h制备的。测试了复合材料的致密化行为和弹性力学性能，分析了VC含量对复合材料致密化和性能的影响。在较低的烧结温度下，VC的加入促进了致密化机制的激活，抑制了烧结过程中ZrB_2和碳化硅的生长。此外，所测得的复合材料的弹性模量、硬度和断裂韧性都是恒定的，与VC含量无关，其剪切模量接近220 GPA，杨氏模量接近500 GPA，硬度接近20 GPA，断裂韧性接近4.4 Mpa m(1/2)。另一方面，复合材料的弯曲强度随着VC含量从3%增加到7%而降低，然后随着VC含量进一步增加到10%而增加，其强度在620-770 Mpa之间。
In this study, highly dense ZrB2-20 vol% SiC composites with 3-10 wt% VC additives were prepared by hot-pressing at 1750 A degrees C for 1 h under a pressure of 20 MPa in a vacuum. The densification behavior and elastic and mechanical properties of the obtained composites were examined, and the effect of the VC content on the densification and the properties is analyzed. The addition of VC promotes the activation of densification mechanism at a lower temperature and inhibits the growth of ZrB2 and SiC grains during the sintering. In addition, the elastic moduli, hardness and fracture toughness that measured in the obtained composites are constant and independent of the VC content, with a shear modulus of similar to 220 GPa, Young's modulus of similar to 500 GPa, hardness of similar to 20 GPa and fracture toughness of similar to 4.4 MPa m(1/2). On the other hand, the flexural strength of the composites decreased as the VC content increased from 3 to 7 wt% and then it increased with further increasing the VC content to 10 wt%, with strength values of 620-770 MPa.