Additive manufacturing (AM) is today in the main focus—and not only in commercial production. Products with complex geometry can be built using various AM techniques, which include laser sintering of metal powder. Although the technique has been known for a quite long time, the impact of the morphology of individual powder particles on the process has not yet been adequately documented. This article presents a detailed microscopic analysis of virgin and reused powder particles of MS1 maraging steel. The metallographic observation was performed using a scanning electron microscope (SEM). The particle size of the individual powder particles was measured in the SEM and the particle surface morphology and its change in the reused powder were observed. Individual particles were analyzed in detail using an SEM with a focused ion beam (FIB) milling capability. The powder particles were gradually cut off in thin layers so that their internal structure, chemical element distribution, possible internal defects, and shape could be monitored. Elemental distribution and phase distribution were analyzed using EDS and EBSD, respectively. Our findings lead to a better understanding and prediction of defects in additive-manufactured products. This could be helpful not just in the AM field, but in any metal powder-based processes, such as metal injection molding, powder metallurgy, spray deposition processes, and others.

Composite materials offer very interesting mechanical and physical properties. Recently, they are an increasingly sought-after commodity particularly in the military, aerospace and automotive industries. This is mainly due to the ratio between their weight and the high values of their mechanical properties, which often reach higher values than commonly used materials. This article is focused on milling of composite materials, specifically fiber reinforced plastics produced by filament winding, in terms of cutting conditions which can be used for good surface quality. The proposal of technology, such as determination of cutting conditions, is a very difficult issue because there are many problems with delamination of reinforcement, high tool wear and with filtering of powder which is formed from the chips of these materials