目的 提高激光选区熔化成形（Selective Laser Melting, SLM）Ti6Al4V合金的表面亲水性。方法 通过调控248 nm KrF准分子激光功率密度和脉冲数，对SLM成形Ti6Al4V合金进行表面改性。利用扫描电子显微镜和激光扫描共聚焦显微镜对激光辐照前后的表面形貌和粗糙度进行表征，利用EDS能谱分析仪和X射线衍射仪对激光辐照后试样的表面成分进行分析，利用接触角测量仪来表征试样表面的浸润性。结果 在50个激光脉冲数下，通过控制准分子激光功率密度为0~531 mJ/cm2，使SLM成形Ti6Al4V表面接触角由(116±4)°减小至(7.5±0.4)°。通过表面形貌观察，激光辐照后的Ti6Al4V表面变得更加平滑，表面粗化现象得到改善。激光辐照后的Ti6Al4V表面粗糙度由(40.3±3.7) μm减小至(8.3±1.7) μm，试样表面与氧气发生反应，导致氧元素质量分数增加至33.54%，且有TiO产生。通过Cassie-Baxter 模型和试样三维表面形貌分析，激光辐照后的Ti6Al4V表面更加光滑，使固-液-气复合界面上固体所占的百分比增加，导致试样变得更加亲水。通过时效性测试，发现试样的表面接触角在48 h内具有稳定性。结论 通过改变准分子激光的功率密度，可以快速高效地降低SLM成形Ti6Al4V合金的表面粗糙度，改善并调控Ti6Al4V的表面亲水性。

The work aims to improve the hydrophilia of selective laser melted (SLMed) Ti6Al4V alloy. The surface of SLMed Ti6Al4V alloy was modified by controlling laser energy density and pulse number of 248 nm KrF excimer laser. Scanning electron microscopy (SEM) and laser scanning confocal microscope (LSCM) were used to characterize the surface morphology and roughness before and after laser irradiation, energy dispersive X-ray spectrum (EDS) and X-ray diffraction (XRD) were employed to analyze the surface components of specimens after laser irradiation and contact angle measuring system was applied to characterize the wettability of specimen surface. When the excimer laser energy density was controlled from 0 to 531 mJ/cm2 with the pulse numbers of 50, the contact angles of specimens decreased from (116±4)° to (7.5±0.4)°. Meanwhile, through surface observation, the surface of Ti6Al4V after excimer laser irradiation became smoother and the surface roughness was improved, decreasing from (40.3±3.7) μm to (8.3±1.7) μm. Moreover, an increase content of oxygen element from 0wt% to 33.54wt% was detected and TiO generated due to the reaction between Ti6Al4V specimens and oxygen. Based on Cassie-Baxter model and 3D surface morphology of the specimens, the surface of Ti6Al4V alloy after laser irradiation became smoother, which increased the percentage of solids in the solid-liquid-gas composite interface, leading to the specimens becoming more hydrophobic. Timeliness test showed that the surface contact angle of the specimens was stable within 48 hours. Therefore, the surface roughness of SLMed Ti6Al4V alloy can be decreased effectively and rapidly and the surface hydrophilia can be improved and controlled by changing energy density of excimer laser irradiation.