Microstructure and Mechanical Properties of ZrB₂⁻HfC Ceramics Influenced by HfC Addition.
Microstructure and Mechanical Properties of ZrB₂⁻HfC Ceramics Influenced by HfC Addition.
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DOI：
10.3390/ma11102046
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发表时间：
2018-10-20
期刊：
影响因子：
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通讯作者：
Lian Z
中科院分区：
文献类型：
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作者：
Jing Y;Yuan H;Lian Z
采用液相烧结技术，通过添加Ni，在1750 °C的低温下制备了ZrB_2-HfC陶瓷。研究了HfC对ZrB 2基陶瓷显微结构和力学性能的影响。这些陶瓷由ZrB 2、HfC、Ni和少量可能的（Zr，Hf）B2固溶体组成。小HfC晶粒分布在ZrB 2晶界之间。这些小晶粒可以提高ZrB 2基陶瓷的致密度，起到钉扎作用。随着HfC含量从10 wt %增加到30 wt %，更多的HfC颗粒分布在ZrB 2晶界之间，导致HfC颗粒间的界面结合减弱，相对密度和维氏硬度增加，抗弯强度和断裂韧性下降。20和30wt%HfC含量的弱界面结合是弯曲强度和断裂韧性下降的主要原因。
ZrB2–HfC ceramics have been fabricated using the liquid phase sintering technique at a sintering temperature as low as 1750 °C through the addition of Ni. The effects of HfC addition on the microstructure and mechanical properties of ZrB2–based ceramics have been investigated. These ceramics were composed of ZrB2, HfC, Ni, and a small amount of possible (Zr, Hf)B2 solid solution. Small HfC grains were distributed among ZrB2 grain boundaries. These small grains could improve the density of ZrB2–based ceramics and play a pinning role. With HfC content increasing from 10 wt % to 30 wt %, more HfC grains were distributed among ZrB2 grain boundaries, leading to weaker interface bonding among HfC grains; the relative density and Vickers hardness increased, and flexural strength and fracture toughness decreased. The weak interface bonding for 20 and 30 wt % HfC contents was the main cause of the decrease in both flexural strength and fracture toughness.