Microstructure and mechanical properties of lanthanum oxide-doped Mo–12Si–8.5B(at%) alloys
Microstructure and mechanical properties of lanthanum oxide-doped Mo–12Si–8.5B(at%) alloys
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DOI：
10.1016/j.jallcom.2012.03.037
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发表时间：
2013-11
影响因子：
6.2
通讯作者：
Zhang Guojun;D. Qian;K. Hao;Wang Rui-hong;L. Gang;S. Jun
中科院分区：
文献类型：
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作者：
Zhang Guojun;D. Qian;K. Hao;Wang Rui-hong;L. Gang;S. Jun
采用电弧熔炼和放电等离子烧结（SPS）技术制备了添加不同质量分数（0、0.6wt%、12wt%）氧化镧（La 2 O3）的Mo-12 Si-8.5B合金。掺杂Mo-12 Si-8.5B合金主要由α-Mo、Mo 3Si和Mo 5SiB 2（T2）相组成。结果表明，添加La 2 O3后，晶粒尺寸减小，金属间化合物颗粒分散更均匀。组织的优化使合金的抗压强度和断裂应变均得到相应的提高。强化机制主要为细晶强化和颗粒弥散强化。此外，断裂韧性测试表明，La 2 O3的加入可以提高Mo-12 Si-8. 5 B合金的韧性，其增韧机制是α-Mo相和大量细小的第二相粒子对裂纹的捕获作用。
Mo–12Si–8.5B alloys with different mass fraction (0, 0.6 wt%, 12 wt%) lanthanum oxide(La2O3) additive were fabricated by using arc-melting and spark plasma sintering (SPS) techniques. The doped Mo–12Si–8.5B alloys are consisted mainly of α-Mo, Mo3Si and Mo5SiB2(T2) phases. It is found that the grains are reduced and the intermetallics particles are dispersed more homogeneously after the addition of La2O3. The optimization in microstructure induces corresponding improvements in both compression strength and breaking strain of the alloys. The predominant strengthening mechanisms are fine-grain strengthening and particles dispersion strengthening. In addition, fracture toughness test shows that the addition of La2O3can improve the toughness of Mo–12Si–8.5B alloys, for which the toughening mechanism involves crack trapping by α-Mo phases and extensive small second phase particles in the alloys.