V-4Cr-4Ti中的析出相及氦离子辐照损伤行为研究

摘要

As one of the most promising candidate structural materials for fusion reactors,the irradiation damage behavior of vanadium alloys has been a research focus.Helium ions with 100 keV were adopted to irradiate V-4Cr-4Ti and China low activity martensitic (CLAM)steels at room temperature.Combined with selected area electron diffraction(SAED),X-ray energy dispersive spectroscopy(EDS)and electron energy loss spectroscopy (EELS),the microstructure especially the precipitate evolution before and after He+irradiation has been inves-tigated by advanced transmission electron microscopy (TEM).The results show that the precipitate present in the vanadium matrix is TiC with FCC structure and they grew along a specific crystal orientation.The length is about 200-1 000 nm.The irradiation of helium ion at room temperature induced lots of fine helium bubbles,ran-ging from 2 to 8 nm in diameter.Distinctly,large bubbles aggregated at the interface between the precipitate and the matrix.The lattice parameters did not change significantly before and after irradiation at the present conditions.Besides,compared with CLAM steel,V-4Cr-4Ti alloy demonstrated better performance of irradia-tion damage resistance.%钒合金作为聚变堆候选结构材料,其辐照损伤行为一直是研究热点.采用100 keV的He+在室温分别对V-4Cr-4Ti与中国低活化马氏体钢CLAM(China low activity martensitic)钢进行辐照实验.利用透射电镜结合选区电子衍射,X射线能谱和电子能量损失谱观察辐照损伤前后显微结构演变及合金元素变化.结果表明,合金内部分布大量呈现针状且沿特定晶体生长方向的面心立方晶系析出相 TiC,长度约为200~1000 nm.室温He+辐照造成V-4Cr-4Ti与CLAM钢内部形成2~8 nm之间的氦泡.钒合金中,析出相与基体界面处的氦泡显著长大,离子辐照并未引起材料显著的晶格膨胀.此外,同一辐照环境下对比 CLAM钢,V-4Cr-4Ti 合金具有更好的抗辐照肿胀性能.