Additive manufacturing of metallic components – Process, structure and properties

Freedom of design, mass customisation, waste minimisation and the ability to manufacture complex structures, as well as fast prototyping, are the main benefits of additive manufacturing (AM) or 3D printing. A comprehensive review of the main 3D printing methods, materials and their development in trending applications was carried out. In particular, the revolutionary applications of AM in biomedical, aerospace, buildings and protective structures were discussed. The current state of materials development, including metal alloys, polymer composites, ceramics and concrete, was presented. In addition, this paper discussed the main processing challenges with void formation, anisotropic behaviour, the limitation of computer design and layer-by-layer appearance. Overall, this paper gives an overview of 3D printing, including a survey on its benefits and drawbacks as a benchmark for future research and development.

Additive manufacturing (3D printing): A review of materials, methods, applications and challenges

Additive manufacturing of metals

Unlike conventional materials removal methods, additive manufacturing (AM) is based on a novel materials incremental manufacturing philosophy. Additive manufacturing implies layer by layer shaping and consolidation of powder feedstock to arbitrary configurations, normally using a computer controlled laser. The current development focus of AM is to produce complex shaped functional metallic components, including metals, alloys and metal matrix composites (MMCs), to meet demanding requirements from aerospace, defence, automotive and biomedical industries. Laser sintering (LS), laser melting (LM) and laser metal deposition (LMD) are presently regarded as the three most versatile AM processes. Laser based AM processes generally have a complex non-equilibrium physical and chemical metallurgical nature, which is material and process dependent. The influence of material characteristics and processing conditions on metallurgical mechanisms and resultant microstructural and mechanical properties of AM proc...

Laser additive manufacturing of metallic components: materials, processes and mechanisms

A study of the microstructural evolution during selective laser melting of Ti–6Al–4V

Additive manufacturing (AM) components can benefit medical applications by improving their functionality and/or providing well fit custom designs. Metal and polymer AM potential can be perfectly expanded to composite materials, such as metal-ceramics, polymer-ceramics, polymer-metal, etc. These components have unique properties that can be beneficial in a variety of end-use industries. The present investigation focuses on the manufacturing and characterization of polyamide-copper composite produced by in-situ laser powder bed fusion, with Cu as a bactericidal agent to reduce risk of infection. A black polyamide PA12/B powder was chosen as a polymer-base to be directly mixed with 10 and 20 wt% Cu contents. A well-studied AM PA2200 material was chosen as a reference material. A characterization study by means of surface roughness, porosity and mechanical properties has been performed. Results showed that the characteristic and properties of the newly developed composite are appropriate and highly promising for medical applications. 

Laser Powder Bed Fusion of Polyamide-composite for Antibacterial Applications: Characterization and Properties

Effective quality control of implants made using additive manufacturing is an important task for suppliers to comply fully with existing regulations and certifications. To study the influence of porosity on the mechanical behaviour of mandibular implants produced by additive manufacturing, preliminary tests with longitudinal flat samples were performed with 3D point bending tests. Ti6Al4V Extra Low Interstitial (ELI) specimens with artificial porosity were designed and subjected to typical loads during mastication. In this work, a finite element simulation was constructed to investigate the bending behaviour of samples, which was consistent with the experimental results. The work shows that even large artificial cavities (designed up to 0.42 mm) do not significantly affect the strength of additively manufactured 2.5 mm-thick Ti6Al4V ELI specimens under typical static loads of mandibular implants, in the considered loading conditions, and for samples subjected to appropriate surface finishing and annealing heat treatment.

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Influence of large artificial porosity on bending behaviour of ti6al4v eli additively manufactured specimens subjected to typical loads during mastication

Igor Yadroitsev

Papers

Laser Powder Bed Fusion of Polyamide-composite for Antibacterial Applications: Characterization and Properties

Influence of large artificial porosity on bending behaviour of ti6al4v eli additively manufactured specimens subjected to typical loads during mastication