【摘要】 激光选区熔化（SLM）成形W-Ni-Fe合金多采用球形钨粉，制备成本较高。本研究提出使用低成本非球形钨粉进行SLM打印90W-7Ni-3Fe的方案，通过优化打印策略控制成形件质量，并深入分析了非球形细钨粉对打印成形件性能的影响。研究结果表明，SLM成形90W-7Ni-3Fe的成形窗口较窄，扫描速度400 mm/s、扫描功率350 W打印的90W-7Ni-3Fe合金质量最好，缺陷和孔隙最少。SEM和EDS结果显示，成形件微观组织由粗W粒子相、近等轴细W区域和低熔点Ni-Fe相区域组成，低熔点金属（Ni/Fe）熔化形成液相，未熔融的钨粒子间隙被液相填充，近等轴细W区域部分钨溶解形成固溶体。采用合适的打印参数与策略，获得了硬度值为601.38±54.33 HV0.2的非球形钨粉SLM打印90W-7Ni-3Fe合金。研究结果可为激光3D打印钨材料成形技术的选择和粉末优化提供参考。更多还原

【Abstract】 Conventional selective laser melting(SLM) of 90W-Ni-Fe alloys predominantly employs spherical tungsten powder, which incurs high preparation costs. This study proposes a low-cost approach utilizing non-spherical tungsten powder for SLM fabrication of 90W-7Ni-3Fe alloy. The printing strategy was optimized to control the quality of formed components. The effects of non-spherical fine tungsten powder on the performance of printed parts were systematically investigated. The results indicate that the process window for SLM-formed 90W-7Ni-3Fe alloy is narrow. Optimal printing quality with minimal defects and porosity was achieved at a scanning speed of 400 mm/s and laser power of 350 W.SEM and EDS analyses revealed that the microstructure of the formed alloy comprises three distinct regions: coarse W particle phases, near-equiaxed fine W regions, and low-melting-point Ni-Fe phase regions. The molten low-melting-point metals(Ni/Fe) formed a liquid phase that filled gaps between unmelted tungsten particles, while partial dissolution of tungsten in the near-equiaxed fine W regions led to solid solution formation. By employing appropriate printing parameters and strategies, a hardness value of 601.38±54.33 HV0.2 was achieved for the SLM-printed 90W-7Ni-3Fe alloy using non-spherical tungsten powder. These findings provide critical insights for parameter selection and powder optimization in laser 3D printing of tungsten-based materials.更多还原