In-situ ZrB2- hBN ceramics with high strength and low elasticity
In-situ ZrB2- hBN ceramics with high strength and low elasticity
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DOI：
10.1016/j.jmst.2020.01.061
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发表时间：
2020-07
影响因子：
10.9
通讯作者：
J. Zou;Guo‐Jun Zhang;Z. Fu
中科院分区：
文献类型：
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作者：
J. Zou;Guo‐Jun Zhang;Z. Fu
采用放电等离子烧结法对添加不同六方氮化硼（hBN）含量（体积分数）的ZrB 2陶瓷进行了反应致密化研究。ZrN-B基添加剂有效地促进了ZrB 2陶瓷的致密化过程，在2000 °C和60 MPa的压力下，原位生成的hBN含量仅为5vol%时，ZrB 2陶瓷的相对密度达到99%以上，而纯ZrB 2陶瓷的相对密度仅为91.2%。随着hBN含量的增加，hBN晶粒由类球形逐渐转变为片状为主，这对材料的力学性能有很大影响，原位ZrB 2 -10 vol%hBN陶瓷具有较高的抗弯强度（597 ± 22 MPa），较低的杨氏模量（406 GPa）和良好的可加工性。特别是其断裂应变高达1.47 × 10−3，比其他同类材料的性能有上级的提高。
ZrB2ceramics with various hexagonal BN (hBN) additions up to 37 vol% were reactively densified by spark plasma sintering using powder mixtures containing ZrB2, ZrN and boron. ZrN-boron based additives effectively promoted the densification process, ZrB2ceramics reached >99 % relative density at 2000 °C and an applied pressure of 60 MPa with only 5 vol%in-situformedhBN, whereas the relative density of pure ZrB2was only 91.2 % at the same conditions. Increasing thehBN contents, the morphology ofhBN grains gradually changed from quasi-spherical to flake dominated, which has substantial influence on their mechanical properties.In-situZrB2-10 vol%hBN ceramics demonstrated high flexural strength of 597 ± 22 MPa, relatively low Young’s modulus of 406 GPa and good machinability, especially for the impressively large strain to failure (1.47 × 10−3) which is superior to most of their counterparts in the ZrB2based particulate reinforced ceramics.