The correct setting of laser beam parameters and scanning strategy for Selective Laser Melting (SLM) technology is a demanding process. Usually, numerous experimental procedures must be taken before the final strategy can be applied. The presented work deals with SLM technology and the impact of its technological parameters on the porosity and hardness of AISI H13 tool steel. In this study, we attempted to map the dependency of porosity and hardness of the tested tool steel on a broad spectrum of scanning speed—laser power combinations. Cubic samples were fabricated under parameters defined by full factorial DOE, and metallurgic specimens were prepared for measurement of the two studied quantities. The gathered data were finally analyzed, and phenomenological models were proposed. Analysis of the data revealed a minimal energy density of 100.3 J/mm${}^3$ was needed to obtain a dense structure with a satisfactory hardness level. Apart from this, the model may be used for approximation of non-tested combinations of input parameters.

Multi jet fusion (MJF) technology has proven its significance in recent years as this technology has continually increased its market share. Recently, polypropylene (PP) was introduced by Hewlett-Packard for the given technology. To our knowledge, little is known about the mechanical properties of polypropylene processed by MJF technology. During this study, standardised specimens were printed under all of the major orientations of the machine’s build space. Each of these orientations were represented by five samples. The specimens then underwent tensile, bending and Charpy impact tests to analyse their mechanical properties. The structural analysis was conducted to determine whether PP powder may be reused within the MJF process. The mechanical tests showed that the orientation of the samples significantly influences their mechanical response and must be carefully chosen to obtain the optimal mechanical properties of PP samples. We further showed that PP powder may be reused as the MJF process does not significantly alter its thermal and structural properties.

This article is focused on a case study of the topology optimisation of a bike stem manufactured by selective laser melting (SLM) additive technology. Topology optimisation was used as a design tool to model a part with less material used for transferring specific loads than the conventional method. For topology optimisation, Siemens NX 12 software was used with loads defined from the ISO 4210-5 standard. Post-processing of the topology-optimised shape was performed in Altair Inspire software. For this case study, the aluminium alloy AlSi10Mg was selected. For qualitative evaluation, the mechanical properties of the chosen alloy were measured on the tensile specimens. The design of the new bike stem was evaluated by Ansys FEA software with static loadings defined by ISO 4210-5. The functionality of the additively manufactured bike stem was confirmed by actual experiments defined by ISO 4210-5. The resulting new design of the bike stem passed both static tests and is 7.9% lighter than that of the reference.

Environmentally-friendly thermoplastic biodegradable polyesters such as polydioxanone (PDO) are becoming increasingly available and are attracting considerable interest in the medical field due to their favourable mechanical properties and degradation to low-toxicity monomers in vivo. These properties are of particular interest in terms of their use in the field of tailored medical implants produced by means of additive manufacturing via 3D printing applying the fused deposition modelling (FDM) technique, also known as fused filament fabrication (FFF). The increasing popularity of this technology in the biomedical community is due mainly to its versatility in terms of the processing approach, structural features and final design. Practically no comprehensive studies have been conducted to date on the 3D printing of polydioxanone. Given the very limited availability of this polymer at a level of quality that allows for its medical application in humans, the aim of this study was to test the use of a commonly available polydioxanone surgical monofilament for the study of its 3D printing potential. PDO comprises a highly crystalline polymer that is susceptible to shrinkage, warpage and adhesion problems. These issues were addressed in the study together with the determination of a range of other printing parameters related to the processing of PDO for FFF 3D printing purposes. The additively produced PDO models evinced similar mechanical properties to PDO samples produced via the classical injection molding technique. Moreover, no negative impact was detected of the printing conditions on the potential degradation of the biodegradable polymer. Thus, the aim to produce PDO models with a high level of printing quality at the microscopic and macroscopic levels with real potential for use in medical applications was achieved.