Densification and mechanical properties of TaC-based ceramics
Densification and mechanical properties of TaC-based ceramics
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DOI：
10.1016/j.msea.2008.09.024
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发表时间：
2009-02
期刊：
影响因子：
6.4
通讯作者：
Xiaohong Zhang;G. Hilmas;W. Fahrenholtz
中科院分区：
文献类型：
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作者：
Xiaohong Zhang;G. Hilmas;W. Fahrenholtz
添加1 wt%或2wt%的B4C可以增强TaC的致密化，同时抑制晶粒长大，从而可以分析其力学性能。在2100℃热压下，添加B4C的TaC的相对密度可达bb0 98%。相比之下，在2300℃下，无添加剂的TaC可以热压到94%的相对密度。x射线衍射分析在TaC-B4C陶瓷中发现了tab2，表明热压过程中发生了反应。力学性能包括杨氏模量、抗弯强度、维氏硬度和断裂韧性。Griffith方程用于根据测量的性能计算临界缺陷尺寸。该分析结合对断口表面的观察，确定了由加工引起的表面缺陷和铣削过程中产生的表面杂质作为关键缺陷。
Densification of TaC was enhanced while the grain growth was suppressed by adding 1 or 2wt% B4C, which allowed mechanical properties to be analyzed. A relative density of >98% was achieved for TaC with B4C additions by hot pressing at 2100°C. By comparison, additive-free TaC could be hot pressed to only 94% relative density at 2300°C. X-ray diffraction analysis identified TaB2in TaC–B4C ceramics, indicating that a reaction occurred during hot pressing. Mechanical properties including Young's modulus, flexure strength, Vickers’ hardness, and fracture toughness were studied. The Griffith equation was used to calculate critical flaw sizes from measured properties. This analysis combined with observations of fracture surfaces identified surface flaws induced by machining and subsurface impurities picked up during milling as the critical flaws.