A continuous electron beam scanning process was used for the surface treatment on U-5.5Nb alloy, under various combinations of beam current, beam accelerating voltage, and scanning speed. The transverse cross-section characteristics of the resulting modification layers were metallographically measured to investigate the relationship between the electron beam processing parameters and the fusion zone geometry or the resolidification microstructure. Results showed that the resolidified modified layers were obtained with the bulk energy density (E₀*) value exceeding 60.7 J/mm³. An “equiaxed-columnar-equiaxed” sandwich-type grain structure was formed in the resolidification fusion zone under the effects of local temperature gradient (G) and the growth rate (R). Different from that of traditional surface modified alloys, the cross-sectional microstructure of surface modified U-5.5Nb alloy consists of four characteristic areas: fusion zone (FZ), heat affected zone (HAZ), base metal (BM), and partially fusion zone (PFZ). The width (W) and depth (D) of the fusion zone had an almost linear increase with the bulk energy density (E₀*). The Vickers hardness, Nb composition, and phase microstructures were also examined. The surface hardness values increased significantly following surface treatment, which was mainly attributed to phase transformation.

在束流，束加速电压和扫描速度的各种组合下，采用连续电子束扫描工艺对U-5.5Nb合金进行表面处理。对所得改性层的横截面特征进行金相测量，以研究电子束加工参数与熔合区几何形状或再凝固微结构之间的关系。结果表明，所得到的固化改性层的体能密度（E ₀ *）值超过60.7 J / mm ³。在局部温度梯度（G）和增长率（R）。与传统的表面改性合金不同，表面改性的U-5.5Nb合金的截面显微组织由四个特征区域组成：熔合区（FZ），热影响区（HAZ），贱金属（BM）和部分熔合区域（PFZ）。融合区的宽度（W）和深度（D）随堆能量密度（E ₀ *）几乎呈线性增加。还检查了维氏硬度，Nb组成和相微结构。表面处理后的表面硬度值显着增加，这主要归因于相变。