基于航空航天领域对轻质高强 Ti2AlNb 基合金的需求，采用激光选区熔化(SLM)技术制备了Ti-22Al-25Nb 合金，系统研究了激光功率、扫描速度及体能量密度(VED)对打印态合金成形质量、显微组织及显微硬度的影响。 结果发现，合金的成形质量受体能量密度显著调控。 当 VED 为 38.89~138.89 J/mm3 时，熔池稳定性良好且致密度最高；而 VED过低(<31.75 J/mm3)或过高(>250 J/mm3)则分别诱发未熔合缺陷与匙孔型气孔。 打印态合金呈沿构建方向外延生长的典型柱状晶组织，其中高能量密度促进了晶粒粗化并形成了显著的 <001> 丝织构；低能量密度下极快的冷却速率则抑制了晶粒生长，使柱状晶细长、破碎且取向趋于随机。 最后，对不同工艺参数下合金的显微硬度进行测试，发现其硬度分布在 242~267 HV 之间。 硬度的演变受致密度与晶粒尺寸的综合影响，中低能量密度下的细晶强化有效弥补了孔隙带来的性能损失，而过高热输入下的晶粒粗化则导致硬度下降。

On the basis of the aerospace industry's demand for lightweight and high-strength Ti2AlNb-based alloys, a Ti-22Al-25Nb alloy was fabricated using selective laser melting (SLM) technology. The effects of laser power, scanning speed, and volumetric energy density (VED) on the forming quality, microstructure, and microhardness of the as-printed alloy were systematically investigated. The results show that the forming quality of the alloy is significantly controlled by the volumetric energy density. When the VED ranges from 38.89 to 138.89 J/mm3,the melt pool exhibits good stability and maximum density; however, both excessively low VED (<31.75 J/mm3)and excessively high VED (>250 J/mm3)induce a lack of fusion defects and keyhole porosity, respectively. The as-printed alloy exhibits a typical columnar grain structure with epitaxial growth along the build direction. High energy density promotes grain coarsening and results in the formation of a pronounced <001> fibrous texture, whereas the extremely rapid cooling rate at low energy density suppresses grain growth, resulting in fine, fragmented columnar grains with a random orientation. Finally, microhardness measurements of the alloys produced under different process parameters reveal a hardness distribution ranging from 242 to 267 HV. The ,hardness evolution is jointly influenced by density and grain size; fine-grained strengthening at medium-low energy density effectively compensates for the performance loss caused by porosity, whereas grain coarsening under excessive heat input leads to a decrease in hardness.