Researchers at Lawrence Livermore National Laboratory have been looking into why porosity is such an issue in metal 3D printing. They have discovered that basically gas flow is responsible for pushing metal powder particles out of the way of the laser, thus causing gaps and defects which ultimately affect the integrity of 3D models. Although several variables can be responsible, the problems occur when powder is directed up or away or to the rear of the laser. With this study, they hope to delve further into the subject and work to refine 3D printing processes so that these defects no longer occur. Read more at 3DPrint.com: https://3dprint.com/137205/metal-3d-...l-researchers/