High temperature tensile properties and their application to toughness enhancement in ultra-fine grained W-(0-1.5)wt% TiC
High temperature tensile properties and their application to toughness enhancement in ultra-fine grained W-(0-1.5)wt% TiC
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DOI：
10.1016/j.jnucmat.2008.12.181
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发表时间：
2009-04-30
影响因子：
3.1
通讯作者：
Yoshida, N.
中科院分区：
文献类型：
--
作者：
Kurishita, H.;Matsuo, S.;Yoshida, N.
超细晶W-TiC固溶体作为聚变堆偏滤器具有很好的应用前景，但其室温塑性的保证问题尚未得到解决。这就需要对固溶体进行足够的塑性加工，从而通过超塑性来克服超细晶W-TiC塑性加工性差的缺点。因此，断裂伸长率和流动应力的大小，这是塑性加工的重要措施，检查为UFG W-（0-1.5）%TiC（重量%）在1673-1973 K，其中发生超塑性没有明显的晶粒生长。结果表明，机械合金化过程中，TiC的加入量和气氛（Ar，H-2）对合金的延伸率和流动应力有很大的影响。随着TiC添加量的增加，延伸率显着增加，而流动应力水平没有明显增加。在H-2气氛中MA制备的W-TiC比在At气氛中MA制备的W-TiC具有更大的延伸率和更大的流变应力应变速率敏感性。将这些结果应用于塑性加工，并给出了塑性加工后W-1.0%TiC的室温弯曲试验结果。(C)2008 Elsevier B. V.保留所有权利。
Ultra-fine grained (UFG) W-TiC consolidates are very promising for use as divertors in fusion reactors, however, the assurance of room-temperature ductility of UFG W-TiC remains unsettled. The assurance requires a sufficient degree of plastic working for the consolidates and thus overcoming of poor plastic workability in UFG W-TiC by applying superplasticity. Therefore, the magnitudes of elongation to fracture and flow stress which are important measures for plastic working were examined for UFG W-(0-1.5)%TiC (in wt%) at 1673-1973 K where superplasticity occurs without appreciable grain growth. It is shown that the elongation and flow stress are strongly dependent on TiC addition and atmosphere (Ar, H-2) during mechanical alloying (MA). As the TiC addition increases, the elongation significantly increases without appreciable increase in the flow stress level. W-TiC fabricated with MA in H-2 exhibits larger elongation and larger strain rate sensitivity of flow stress than W-TiC with MA in At. These results were applied to perform plastic working and the room-temperature bend test results for plastic worked W-1.0%TiC are shown. (C) 2008 Elsevier B.V. All rights reserved.