Fe-(9~11)Cr-Y2O3作为ITER结构材料的制备与表征

采用传统的机械合金(MA)和放电等离子体烧结(SPS)工艺成功制备了Fe-(9~11)Cr二元合金及纳米氧化物弥散强化(ODS)合金，利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)对MA粉末的形貌和物相进行分析，用能量色散谱(EDS)、显微维氏硬度仪、光学显微镜、透射电子显微镜(TEM)对合金样品进行表征。结果表明，在转速为300 r/min，球料比为10:1的条件下，MA粉末受到磨球与罐子内壁的撞击，晶粒尺寸不断细化，在40 h粉末晶粒尺寸减小至约16.1 nm趋于稳定。SPS烧结后晶粒尺寸无明显增大，各微量元素均匀分布在基体中。二元合金样品的维氏硬度随Cr含量增加而增大。10CrY合金样品经腐蚀液侵蚀后可粗略看到晶界呈均匀分布。ODS合金样品存在大量的纳米析出相，平均颗粒尺寸约30 nm。

Processing and characterization of Fe-(9~11)Cr-Y2O3 as ITER structural material

Oxide dispersion strengthened (ODS) steel has excellent radiation properties and is considered a candidate for the first wall structure of fusion reactors. Adding Y element to the material can improve thermal stability, and Cr element can improve corrosion resistance, because the high oxide density inside will cause needle-like dislocations, the material has higher strength and lower toughness to brittle transition temperature. The nano-precipitation phase can trap helium and make it in the form of nano-scale helium bubbles, avoiding the production of large helium bubbles to reduce possibility of expansion. Reducing helium embrittlement can make the material have a longer service life in the fusion reactor. In this work, based on mechanical alloying (MA) and spark plasma sintering (SPS), binary alloys with Fe(9~11)Cr content and ODS alloys were prepared successfully. The morphology and phase analysis of MA powders were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), micro Vickers-hardness tester and energy dispersive spectrum (EDS), and the precipitation phase of the alloy sample was observed by transmission electron microscope (TEM). The results showed that the fine grain size enabled the material to have good tensile and creep properties at high temperatures. The MA powder was continuously refined after being crushed and deformed under a rotational speed of 300 r/min and the ball-to-powder mass ratio was 10:1. The MA powder reached the cold welding-crushing balance at 40 h. The powder grain size decreased to about 16.1 nm and tended to be stable with the increase of ball grinding time. After spark plasma sintering and solidification of the MA powder for 40 h, the grain size did not increase significantly, and the trace elements were uniformly distributed in the matrix. The Vickers-hardness of binary alloy samples increased with the addition of Cr content. The grain boundaries of ODS alloy samples proved to be fine and uniform after being eroded by corrosive liquid.