The work presented in this thesis was conducted at Uppsala University and at Swerim AB. The study aims to broaden the knowledge about the corrosion of additively manufactured bioresorbable alloy WE43 in humanlike conditions for future applications. Biodegradable metal implants are implants meant to stay in the body and support the wounded bone for a certain time period, and then degrade as new, healthy bone forms in its place. Magnesium alloys have properties that are desired for these kind of implants as it is biodegradable, non-toxic and matches the mechanical properties of bone. Furthermore, magnesium alloy WE43, containing yttrium, neodymium and zirconium, already exist on the market as a powder extruded screw that treats Hallux valgus, thus proves the alloys compatibility as a bioresorbable implant. However, in order to optimize implants for specific situations, additive manufacturing can be a powerful tool. By utilizing the advantages of additive manufacturing, patient specific, complex designs implant can be manufactured rapidly in order to be used in a patient. On the other hand, additive manufacturing is a complex method with many aspects affecting the outcome. Therefore it is important to study the influence that different parameters have on the material's properties, especially the corrosion properties. This thesis aims to study different power settings on the laser in the manufacturing process and what effect it has on the microstructure as well as the corrosion properties of as built WE43 samples. Samples of three different parameters settings were manufactured with a Powder Bed Fusion-Laser Beam 3Dprinter. These samples were analyzed regarding surface roughness and microstructure with Light Optical Microscope, Scanning Electron Microscope, Energy Dispersive Spectroscopy, Electron Backscatter Diffraction and Alicona InfiniteFocus. Furthermore, the corrosion properties of the samples were investigated by collecting and measuring hydrogen gas that is released during the corrosion process. In addition, the electrolyte were examined regarding the change in ion concentration and electrochemical tests were performed. It was found that the samples did not differ substantially in microstructure as all three parameter settings exhibited a matrix of magnesium and precipitates of alloying elements. However, the sample manufactured at the lowest energy density had pores incorporated in the bulk. Despite the porous bulk this sample performed best in the immersion tests and exhibited the lowest corrosion rate over 28 days. The reason for this behavior is not determined, however possible causes are discussed and further studies are recommended.

Denna studie undersöker möjligheten att ta fram en mer hållbar och cirkulär armatur i ett samarbete med ateljé Lyktan i Åhus, där utgångspunkten är deras armatur RIFF pendel. Studien utgår huvudsakligen utifrån ett materialperspektiv där en översyn av delar inom armaturen ses över för att skapa en cirkularitet kring produkten. Teorin har sin utgångspunkt inom design för hållbar utveckling där förhållandet till cirkulär ekonomi ligger i fokus, detta för att utforska med ett materialdrivet designperspektiv utgå från själva materialet med krav som en huvudkaraktär i utformandet. För att uppnå ett resultat och slutsats utförs en förstudie som research metod och en designspecifikation skapas för att sammanställa allt som armaturen ska klara av att lösa och bidra med. Researchen följs upp av en designprocess för att undersöka och konkretisera de designmål och kriterier som produkten behöver uppnå. Studien ger förslag till ateljé Lyktan i form av en skärm och och uppgradering av befintliga ljusmotorn för RIFF armatur med ett cirkulärt material från en förnybar resurs. / This study examines the possibility of developing a more sustainable and circular luminaire in collaboration with ateljé Lyktan in Åhus, based on their RIFF pendant luminaire. The study primarily focuses on a material perspective, reviewing parts within the luminaire to create circularity around the product.  The theory is based on design for sustainable development where the relationship to the circular economy is in focus, this to explore with a material driven design perspective starting from the material itself with requirements as a main character in the design. To achieve a result and conclusion, a preliminary study is conducted as a research method, and a design specification is created to compile all the aspects that the luminaire needs to solve and contribute to. The research is followed by a design process to investigate and concretize the design goals and criteria that the product needs to achieve. The result of this study provides suggestions to ateljé Lyktan in the form of a shade and an upgrade of the existing light engine for the RIFF luminaire with a circular material from a renewable resource.

The relatively new and still growing field of 3D-printing has opened up the possibilities to manufacture patient-specific medical devices with high geometrical accuracy in a precise and quick manner. Additionally, biocompatible materials are a demand for all medical applications while biodegradability is of importance when developing scaffolds for tissue growth for instance. With respect to this, this project consisted of developing biocompatible and bioresorbable polymer blend and composite filaments, for fused deposition modeling (FDM) printing. Poly(lactic acid) (PLA) and polycaprolactone (PCL) were used as supporting polymer matrix while hydroxyapatite (HA), a calcium phosphate with similar chemical composition to the mineral phase of human bone, was added to the composites to enhance the biological activity. PLA and PCL content was varied between 90–70 wt% and 10-30 wt%, respectively, while the HA content was 15 wt% in all composites. All materials were characterized in terms of mechanical properties, thermal stability, chemical composition and morphology. An accelerated degradation study of the materials was also executed in order to investigate the degradation behavior as well as the impact of the degradation on the above mentioned properties. The results showed that all processed materials exhibited higher mechanical properties compared to the human trabecular bone, even after degradation with a mass loss of around 30% for the polymer blends and 60% for the composites. It was also apparent that the mineral accelerated the polymer degradation significantly, which can be advantageous for injuries with faster healing time, requiring only support for a shorter time period.