Wei Boxin, Wang Dong, Wang Yujin, Zhang Haibin
School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China.
Institute for Advanced Ceramics, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Materials (Basel). 2019 Nov 16;12(22):3768. doi: 10.3390/ma12223768.
ZrC ceramics with different stoichiometries were irradiated under a four MeV Au ion beam in doses of 2 × 10 ions/cm at room temperature, corresponding to ~130 dpa. Grazing incidence, X-ray diffraction and transmission electron microscopy were performed to study the radiation damage and microstructure evolution in ZrC ceramics. With the decrease in C/Zr ratio, the expansion of ZrC lattice became smaller after irradiation. Some long dislocation lines formed at the near-surface, while, in the area with the greatest damage (depth of ~400 nm), large amounts of dislocation loops formed in ZrC, ZrC and ZrC. With the increase in carbon vacancy concentration, the size of the dislocation loops gradually decreased. Few dislocation loops were found in ZrC after irradiation, and only black-dot defects were found in the area with the greatest damage. For the non-stoichiometric ZrC, with the increase of the intrinsic vacancies, the number of C interstitials caused by irradiation decreased, and the recombination barrier of C Frenkel pairs reduced. The above factors will reduce the total number of C interstitials after cascade cooling, suppressing the formation and growth of dislocation loops, which is significant for the enhancement of the tolerance of radiation damage.
在室温下，用能量为4兆电子伏的金离子束以2×10离子/平方厘米的剂量辐照不同化学计量比的ZrC陶瓷，对应约130 dpa。采用掠入射X射线衍射和透射电子显微镜研究ZrC陶瓷中的辐射损伤和微观结构演变。随着C/Zr比的降低，辐照后ZrC晶格的膨胀变小。在近表面形成了一些长位错线，而在损伤最大的区域（深度约400纳米），ZrC、ZrC和ZrC中形成了大量位错环。随着碳空位浓度的增加，位错环的尺寸逐渐减小。辐照后ZrC中几乎没有位错环，在损伤最大的区域仅发现黑点缺陷。对于非化学计量比的ZrC，随着本征空位的增加，辐照引起的C间隙原子数量减少，C弗伦克尔对的复合势垒降低。上述因素将减少级联冷却后C间隙原子的总数，抑制位错环的形成和生长，这对提高辐射损伤耐受性具有重要意义。
