中文摘要：

为提高合金的力学性能，在温度950°C不同应变和应变速率条件下对SLM成形的Ti6Al4V合金试样进行精密锻造处理，使用光学显微镜和X射线衍射仪分析原试样和锻造处理试样在水平和竖直截面内显微组织的演化，并计算了每个截面的孔隙率。结果表明，大应变速率以及大变形量可以改善显微组织并降低孔隙率，进而提高材料的疲劳性能。精密锻造处理后的试样显微硬度小于SLM成形原件的显微硬度；同时，精密锻造处理试样在水平截面和竖直截面的显微硬度差小于SLM成形原件在两个截面的显微硬度差。这说明精密锻造工艺可以改善SLM成形零件的各向异性。

英文摘要：

To improve the mechanical properties of Ti6Al4V alloy prepared by selective laser melting(SLM)process,the precision forging was conducted at950°C and different strains and strain rates.The microstructure evolution of as-built samples and forged samples in both horizontal and vertical sections was visualized and analyzed by optical microscope and X-ray diffraction.The microstructure was improved by the precision forging and subsequent water quenching.The porosity in each section was accounted.It can be seen that high strain rate and large deformation result in low porosity,consequently contributing to a better fatigue performance.The micro-hardness was lowered after precision forging and water quenching,while the difference of microhardness between the horizontal and vertical sections became smaller,which illustrated that this process can improve the anisotropy of structural components fabricated by SLM.