Ar离子辐照对Zr-0.75Sn-1Nb-0.35Fe-0.15Cr合金显微组织和耐腐蚀性能的影响  

Effect of Ar Ion Irradiation on Microstructure and Corrosion Resistance of Zr-0.75Sn-1Nb-0.35Fe-0.15Cr Alloy

作　　者：顾志远 吴悦 林晓冬 姚美意[1] 胡丽娟[1] 梁雪[2] 李毅丰 彭剑超[2] 谢耀平[1] 周邦新[1] Gu Zhiyuan;Wu Yue;Lin Xiaodong;Yao Meiyi;Hu Lijuan;Liang Xue;Li Yifeng;Peng Jianchao;Xie Yaoping;Zhou Bangxin(Institute of Materials,Shanghai University,Shanghai 200072,China;Laboratory for Microstructures,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料研究所,上海200072 [2]上海大学微结构重点实验室,上海200444

出　　处：《稀有金属材料与工程》2024年第6期1642-1653,共12页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展计划(2022YFB1902400);国家自然科学基金(52201079)。

摘　　要：通过熔炼、热轧、冷轧和退火等工艺制备了Zr-0.75Sn-1Nb-0.35Fe-0.15Cr(质量分数,%)合金板状样品,采用静电加速器在300℃下对样品进行注量为1.02×10^(15)和5.1×10^(15)ions/cm^(2)(对应辐照损伤剂量分别为1和5 dpa)的Ar^(+)辐照,然后将未辐照和辐照样品置于360℃/18.6 MPa/0.01 mol·L^(-1)Li OH水溶液中腐蚀90 d,利用SEM和TEM表征分析了辐照前后合金基体显微组织和腐蚀后氧化膜截面显微组织。结果表明,辐照前Zr-0.75Sn-1Nb-0.35Fe-0.15Cr合金为完全再结晶组织,晶粒呈等轴晶,第二相主要为fcc和hcp结构的Zr(Fe,Cr,Nb)_(2),尺寸主要在50~100 nm范围内;辐照后,合金内形成了型位错环,第二相发生了完全非晶化,但未发现第二相中元素向基体扩散现象。腐蚀90 d后,辐照样品的氧化膜厚度小于未辐照样品,说明Ar^(+)辐照在一定程度上降低了合金腐蚀初期的腐蚀速率。分析认为,Ar^(+)辐照能延缓氧化膜显微组织的演化,降低氧化膜中的等轴晶占比和裂纹数量,同时辐照诱导的非晶化第二相的氧化更慢,使氧化膜更具保护性,从而降低合金的腐蚀速率。Zr-0.75Sn-1Nb-0.35Fe-0.15Cr(wt%)alloy plates were prepared by smelting,hot rolling,cold rolling and annealing techniques successively.The samples were then irradiated on an electrostatic accelerator with Ar^(+)to a influence of 1.02×10^(15)and 5.1×10^(15)ions/cm^(2)(corresponding to 1 dpa and 5 dpa,respectively)at 300℃.Both the unirradiated and irradiated samples were exposed to 360℃/18.6 MPa/0.01 mol/L LiOH aqueous solution for 90 d.The microstructures of the alloy matrix before and after irradiation and the oxide film formed after corrosion were characterized by SEM and TEM.The results show that before irradiation the alloy is fully recrystallized and the grains are equiaxed.The second phase particles are mainly Zr(Fe,Cr,Nb)_(2)with a fcc or hcp structure,and their size is within the range of 50100 nm.After irradiation,-type dislocation loops were observed in the irradiated region of the alloy,and the second phase particles are completely amorphous,but the element diffusion from the second phase particles to the matrix is not found.After corrosion for 90 d,the oxide film of the irradiated samples is thinner than that of the unirradiated sample,indicating that Ar^(+)irradiation decreases the corrosion rate of the alloy to some extent at early stage of corrosion.This can be explained by the fact that Ar^(+)irradiation could delay the microstructural evolution of oxide film,including reducing the proportion of equiaxed grains and the number of cracks in the oxide film,as well as slowing down the oxidation of amorphous second phase particles induced by irradiation,thus enhancing the protectiveness of the oxide film.

关 键 词：锆合金 辐照 腐蚀 氧化膜 第二相 

分 类 号：TL341[核科学技术—核技术及应用] TG146.414[一般工业技术—材料科学与工程]