In present study, the feasibility of wire-based additive manufacturing of commercially pure tungsten using electron beam technique could be demonstrated. Three different representative volumetric AM structures were built and subsequently characterized. The parts show a sound visual appearance with the absence of macroscopic cracks or severe distortion. The fabricated parts exhibit high density and the value depends on the welding sequence applied; while the thin- and medium-walled structure has a relative density of ~100% and 99.875%, the measured relative density of the volumetric structure is slightly reduced to ~99.131% due to the smaller periodic bonding defects. However, a higher density could be achieved compared to powder-based processes on refractory metal. The mean hardness value of the fabricated AM structures is approx. 366–380 HV1 and is in the range of approx. 89–93% of the conventionally fabricated substrate of 410 ± 39 HV1. A coarsening of the grains from the bottom to the top and a change in morphology can be noted for all AM structures. While the coarsening is quite severe for the thin-walled structure, it is moderate for the volumetric AM structures due to the change of the thermal boundary conditions. Caused by the deposition process, the microstructure in the substrate also changes and exhibits a coarse-grained heat-affected zone. Nevertheless, the grain size is still smaller compared to the AM bulk material.

在本研究中，可以证明使用电子束技术对商业纯钨进行基于线材的增材制造的可行性。构建了三种不同的具有代表性的体积增材制造结构并随后对其进行了表征。零件显示出良好的视觉外观，没有宏观裂纹或严重变形。制造的零件具有高密度，其值取决于所应用的焊接顺序；虽然薄壁和中壁结构的相对密度为~100% 和 99.875%，但由于周期性结合缺陷较小，体积结构的测量相对密度略微降低至~99.131%。然而，与基于粉末的难熔金属工艺相比，可以实现更高的密度。制造的 AM 结构的平均硬度值约为。366–380 HV1，范围约为。410 ± 39 HV1 的常规制造基板的 89–93%。对于所有 AM 结构，可以注意到从底部到顶部的晶粒粗化和形态变化。虽然薄壁结构的粗化非常严重，但由于热边界条件的变化，体积AM结构的粗化是适度的。由于沉积过程，基板中的微观结构也发生了变化，并呈现出粗晶热影响区。尽管如此，与AM散装材料相比，晶粒尺寸仍然更小。虽然薄壁结构的粗化非常严重，但由于热边界条件的变化，体积AM结构的粗化是适度的。由于沉积过程，基板中的微观结构也发生了变化，并呈现出粗晶热影响区。尽管如此，与AM散装材料相比，晶粒尺寸仍然更小。虽然薄壁结构的粗化非常严重，但由于热边界条件的变化，体积AM结构的粗化是适度的。由于沉积过程，基板中的微观结构也发生了变化，并呈现出粗晶热影响区。尽管如此，与AM散装材料相比，晶粒尺寸仍然更小。