Effects of LaB6 content on microstructure and mechanical properties of TaC-LaB6 composites
Effects of LaB6 content on microstructure and mechanical properties of TaC-LaB6 composites
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LaB6含量对TaC-LaB6复合材料显微组织和力学性能的影响
DOI：
10.1016/j.matchemphys.2018.04.060
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发表时间：
2018
影响因子：
4.6
通讯作者：
Chen Yuhong
中科院分区：
文献类型：
--
作者：
Lu Zhuang;Liu Limeng;Hou Zhaoping;Geng Guihong;Wang Yujing;Sun Wenzhou;Hai Wanxiu;Chen Yuhong
通过在1900 °C和30 MPa压力下热压30 min制备了含有0.1-30 mol%六硼化镧（LaB 6）的碳化钽（TaC）基复合材料。研究了LaB 6含量对TaC-LaB 6复合材料致密化、显微结构和力学性能的影响。在1950 °C温度下进行烧结-锻造以测试TaC-LaB 6复合材料的抗蠕变性。LaB 6的加入提高了TaC-LaB 6复合材料的致密度，当LaB 6含量≥ 1mol%时，复合材料几乎达到全密度。LaB 6与TaC和Ta 2 O3杂质反应生成TaB 2、B2 O3和C的副相。随着LaB 6含量的增加，TaC晶粒的平均尺寸呈减小趋势。LaB 6添加量为1/2mol%时，TaC-LaB 6复合材料具有较好的抗弯强度、维氏硬度和断裂韧性，分别为530 MPa、15.6 GPa和5.29 MPa m1/2。LaB 6的加入改善了TaC晶粒的界面结合强度，从而提高了烧结-锻造温度高达1950 °C时的抗蠕变性能。
Tantalum carbide (TaC)-based composites containing 0.1–30 mol% lanthanum hexaboride (LaB6) were prepared by hot pressing at 1900 °C for 30 min under 30 MPa pressure. Effects of LaB6content on densification, microstructure and mechanical properties of the consolidated TaC-LaB6composites were investigated. Sinter-forge was performed to test creep resistance of the TaC-LaB6composites at temperatures up to 1950 °C. Addition of LaB6increased densification of the TaC-LaB6composites and the compositions with ≥1 mol% LaB6almost reached full densities. LaB6reacted with TaC and the Ta2O3impurity to form minor phases of TaB2, B2O3and C. Average size of the TaC grains in the consolidated composites showed a decrease trend with increase in the LaB6content. The TaC-LaB6composites with 1–2 mol% LaB6addition had relatively good flexural strength, Vickers hardness and fracture toughness with a value of 530 MPa, 15.6 GPa and 5.29 MPa m1/2, respectively. Addition of LaB6modified interfacial bonding strength of the TaC grains, hence increase in creep resistance under sinter-forge up to 1950 °C.