7075铝合金的Fe^(11+)离子辐照损伤研究

Study on Fe^(11+)ion irradiation damage of 7075 aluminum alloy

7075铝合金因其优异的各项性能,作为结构部件,广泛应用于航天领域中。航天器空间环境中存在各种辐射粒子,这些粒子会对航天器材料产生不同程度的辐照损伤,对其可靠性构成了巨大的威胁,甚至会导致航天任务失败。通过选取不同剂量下3 MeV的Fe^(11+)离子辐照7075铝合金,采用XRD、AFM和纳米压痕等测试手段对7075铝合金的辐照损伤进行了研究,分析了辐照前后7075铝合金的微观组织、表面形貌和硬度的变化。结果显示,离子辐照后的7075铝合金未形成新的相,且结构保持完整,表明其具有一定的抗辐照性能。同时,观察表面发现了由级联碰撞演化及表面缺陷扩散导致的山峰状突起,且样品表面粗糙度和突起的分布密度随剂量增加呈先增加后减小的趋势。另外,纳米压痕测试表明,辐照后样品硬度增加,且随剂量增加,硬度逐渐趋于饱和,经分析可知,样品产生辐照硬化是由于辐照缺陷阻碍了位错的滑移导致。

7075 aluminum alloy is widely used in the field of aerospace materials as a structural component due to its excellent properties.There are various radiation particles in the spacecraft space environment,which will cause different degrees of irradiation damage to spacecraft materials,and threaten their reliability,and even lead to failure of space missions.Selecting different doses of 3 MeV Fe^(11+)ions to radiate the 7075 aluminum alloy,using XRD,AFM and nanoindentation to study the microstructure,surface morphology and hardness changes before and after irradiation,the tapered protrusions caused by cascade collision evolution and surface defect diffusion are found on the surface and the surface roughness of the sample increased first and then decreased with the increase of dose.In addition,the nanoindentation test shows that the hardness of the sample increased after irradiation,and with the increase of dose,the hardness gradually became saturated.The analysis shows that the irradiation hardening of the sample is caused by the irradiation defects impeding the slippage of dislocations.