As a typical additive manufacturing technique, direct energy deposition is restricted from further application due to the presence of residual stress and the structural deformation. Thus, minimizing the residual stress plays a crucial role in additive manufacturing. In this work, a transverse static magnetic field is introduced in the laser remelting of Inconel 718 superalloy to investigate the effects on residual stress and microstructural change. The x-ray diffraction technique was used to examine the residual stress variation. Optical microscope and scanning electron microscope were applied to observe the microstructure evolution. It was found that the compressive residual stress of the remelted region was notably reduced from 392.50 to 315.45 MPa under the effect of the magnetic field of 0.55 T. Furthermore, it was observed that the average dendrite spacing was reduced by about 32% under the magnetic field. During the laser remelting process, the imposed electromagnetic force minimized the flow field within the molten pool, inhibiting the heat transfer and minimizing the cooling rate. These directly reduced the residual stresses. Based on research findings, the magnetic field can be a potential method to eliminate the residual stress in laser additive manufacturing components.

中文翻译：

---

静磁场对激光重熔Inconel 718高温合金残余应力和组织演变的影响

作为一种典型的增材制造技术，由于存在残余应力和结构变形，直接能量沉积限制了进一步应用。因此，最小化残余应力在增材制造中起着至关重要的作用。在这项工作中，在 Inconel 718 高温合金的激光重熔中引入横向静磁场，以研究对残余应力和微观结构变化的影响。X 射线衍射技术用于检查残余应力变化。应用光学显微镜和扫描电子显微镜观察微观结构演变。结果表明，在0.55 T磁场作用下，重熔区残余压应力从392.50 MPa显着降低到315.45 MPa。此外，据观察，在磁场作用下，平均枝晶间距减少了约 32%。在激光重熔过程中，施加的电磁力使熔池内的流场最小化，抑制了热传递并最小化了冷却速度。这些直接降低了残余应力。根据研究结果，磁场可以成为消除激光增材制造部件中残余应力的潜在方法。