强流脉冲电子束作用下纯镍表面的应力特征

 利用强流脉冲电子束（HCPEB）装置对多晶纯镍进行轰击，采用X射线衍射及扫描电子显微镜等技术，详细分析了受轰击样品的变形组织与结构。通过分析建立了强流脉冲电子束诱发的应力特征与变形结构之间的关系，并对目前现有的几种应力波数值模拟结果进行了讨论。实验结果表明：强流脉冲电子束能够在材料表层诱发约5GPa的应力，造成纯镍表面发生孪生塑性变形。除了热膨胀引起的表层横向准静态热应力外，强流脉冲电子束产生的等离子体脉冲爆炸可以直接诱发幅值很高的冲击应力波，二者的共同作用是引起表层微观结构变化的直接原因。

Surface Stress Characteristics in Pure Nickel after High-Current Pulsed Electron Beam Irradiation

Polycrystalline nickel samples were irradiated with high-current pulsed electron beam (HCPEB). The induced deformation structures were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relationship between the stress characteristics induced by HCPEB irradiation and the deformation structures was established, and the current numerical simulation results of stress were discussed. The experimental results showed that stress with about 5 GPa had been introduced in the irradiated surface layer, which led to severe plastic deformation (e.g., twin deformation) on the irradiated surface. Both the quasi-static thermal stress and the impact stress wave that induced by plasma pulsed explosion during the HCPEB processing are the main cause of the surface microstructure changes.