论文标题
定向能量沉积添加剂制造的原位和操作数X射线成像
In situ and Operando X-ray Imaging of Directed Energy Deposition Additive Manufacturing
论文作者
论文摘要
定向能量沉积添加剂（DED-AM）组件的机械性能可能是高度依赖的。通过原位和Operando同步X射线成像，我们捕获了控制不锈钢（SS316）和钛合金（TI6242或TI-6AL-2SN-4ZR-2MO）的基本现象。我们揭示了与不锈钢相比，影响钛合金的建筑效率的三种机制：吹粉末烧结；减少了由于烧结物而导致的熔体润湿；孔推入融化池。前两个直接增加了缺乏融合孔隙率，而后者则导致轨道孔隙率的末端。每种现象都会影响熔体池特征，底物的润湿，从而建立功效和不良的微观结构特征形成。我们证明孔隙度与粉末特性，池流量和固化前形态有关。我们的结果阐明了DED-AM流程动力学，说明了为什么每种合金都以不同的方式构建，从而促进了添加剂制造在新材料中的更广泛应用。
The mechanical performance of Directed Energy Deposition Additive Manufactured (DED-AM) components can be highly material dependent. Through in situ and operando synchrotron X-ray imaging we capture the underlying phenomena controlling build quality of stainless steel (SS316) and titanium alloy (Ti6242 or Ti-6Al-2Sn-4Zr-2Mo). We reveal three mechanisms influencing the build efficiency of titanium alloys compared to stainless steel: blown powder sintering; reduced melt-pool wetting due to the sinter; and pore pushing in the melt-pool. The former two directly increase lack of fusion porosity, while the later causes end of track porosity. Each phenomenon influences the melt-pool characteristics, wetting of the substrate and hence build efficacy and undesirable microstructural feature formation. We demonstrate that porosity is related to powder characteristics, pool flow, and solidification front morphology. Our results clarify DED-AM process dynamics, illustrating why each alloy builds differently, facilitating the wider application of additive manufacturing to new materials.
