强脉冲离子束辐照金属材料烧蚀产物特性分析

摘要

Intense pulse ion beam (IPIB) has been extensively used in material surface modification. The ablation effect plays an important role in the interaction between IPIB and material. Therefore, the understanding of ablation mechanism is of great significance for IPIB application. Here, to investigate the ablation process and the characteristics of ablation products, pure zinc targets are bombarded by IPIB of 1.2–1.5 J/cm2 energy density at TEMP-4M accelerator. The ablation products are collected by monocrystalline silicon substrates in the IPIB irradiation process. By using the scanning electron microscopy, energy dispersive spectrometer and high precision balance, the surface morphology of the substrate and the characteristics of ablation products are obtained. The majority of observed ablation products are nearly circular particles with diameters of 0.03–2.00 μm. There are a small number of zinc droplets and solid debris with large irregular shapes on the silicon substrate. Combining Monte Carlo method and infrared imaging diagnostic results, a heat conduction model is constructed by finite element method to describe the distribution and evolution of thermal field formed by IPIB on a zinc target. The results show that the zinc target can be melted and evaporated under a 1.2 J/cm2 IPIB irradiation. By comparing the experimental resuls with the simulation results, it is found that the gaseous, liquid and solid ablation products are generated collectively in the zinc ablation process. The causes of the different ablation products are also studied.%强脉冲离子束作为一种闪光热源在材料表面改性方面具有广泛的应用.烧蚀效应对于强脉冲离子束与物质相互作用以及强脉冲离子束薄膜沉积过程具有重要的影响.因此,分析强脉冲离子束的烧蚀过程和机理对于优化其应用具有重要意义.为了研究强脉冲离子束的烧蚀产物特性,采用1.2—1.5 J/cm2的强脉冲离子束辐照纯锌靶材,并使用单晶硅片收集辐照过程中产生的烧蚀产物.通过扫描电子显微镜、能谱仪和高精度天平的分析与测量,得到了烧蚀产物的表面形貌和相关特性等实验结果.结合实验和有限元模拟计算得到的材料表面温度场分布演化结果,可以证明在强脉冲离子束辐照锌靶材的烧蚀过程中会有气态、液态和固态三种不同状态的烧蚀产物产生.