Papers by Keyword: Electron Beam Melting (EBM)

Abstract: An investigation of HIP parameters for EBM Ti-6Al-4V has been performed with the aim to maximize the strength of the HIPed material. A lower HIP temperature of 800 °C and a higher pressure of 200 MPa gives the highest strength and is also enough to eliminate all internal defects. By printing material with intentionally induced porosity combined with an optimized HIP cycle the highest strength can be obtained.

Abstract: 3D-printing or additive manufacturing (AM) is a group of novel intensively developed production processes, through which a "printed" object is fabricated layer-by-layer in a desired intricate geometrical shape with following joining it into a monolithic bulk by means of electron beam (EB) or laser beam (LB) melting. The present study is concentrated on the production of simple-shaped (cylindrical) Ti-6Al-4V alloy samples by Electron Beam Melting (EBM). During the rapid cooling of as-printed material's layer, martensitic structure is formed while suppressing of material's diffusivity. Effect of heat transfer conditions on the microstructure and properties obtained has been investigated. Heat transfer modelling and simulation was done utilizing the ABAQUS software package. The microstructure of the obtained material has been characterized by means of SEM and XRD. Microhardness have been also determined and correlated with the simulation results.

Abstract: We proposed a new biomaterial composed of solid and powder cubic compartments to exhibit isotropic or bone-mimic one-dimensional anisotropic mechanical properties. The raw material used was gas-atomized Ti-6Al-4V ELI powder comprising spherical particles with a diameter of approximately 80 μm. Cube-shaped products composed of 27 (3 × 3 × 3) unit cubic compartments occupied by solid or powder part were designed using three-dimensional CAD. The products were fabricated by electron beam melting (EBM) (Arcam AB, Sweden) according to the specifications shown in a CAD drawing. The residual unmelted powder in the products does not need to be removed to make the products more mechanically integrated. Moreover, the layout of the powder and solid compartments in the products were arranged to achieve isotropy resembling a face-centered cubic atomic arrangement or a long-bone-mimic mechanical anisotropy with square prismatic columns. The products demonstrate isotropic or anisotropic Young’s modulus, yield stress, and toughness, all of which can be changed by CAD design and EBM. In conclusion, novel powder/solid materials comprising solid cubic parts and functionalized powder particles between them were successfully developed, which could be useful in biomedical and industrial applications.

Abstract: Additive manufacturing (AM) is becoming one of the most discussed modern technologies. Significant achievements of the AM in metals today are mainly connected to the unprecedented freedom of component shapes this technology allows. But full potential of these methods lies in the development of new materials designed to be used specifically with AM. Proper understanding of the AM process will open up new possibilities, where material and component properties can be specifically tailored by controlling the parameters throughout the whole manufacturing process. Present paper discusses the issues related to the beam melting technologies AM and electron beam welding (EBW). We are speaking of new direction in material science that can be termed “non-stationary metallurgy”, using the examples from material and process development for EBW, electron beam melting (EBM^®) and other additive manufacturing methods.

Abstract: Custom orthopedic and dental implants may be fabricated by additive manufacturing (AM), for example using electron beam melting technology. This study is focused on the modification of the surface of Ti6Al4V alloy coin-like scaffolds fabricated via AM technology (EBM®) by radio frequency (RF) magnetron sputter deposition of hydroxyapatite (HA) coating. The scaffolds with HA coating were characterized by Scanning Electron microscopy, X-ray diffraction. HA coating showed a nanocrystalline structure with the crystallites of an average size of 32±9 nm. The ability of the surface to support adhesion and the proliferation of human mesenchymal stem cells was studied using biological short-term tests in vitro. In according to in vitro assessment, thin HA coating stimulated the attachment and proliferation of cells. Human mesenchymal stem cells cultured on the HA-coated scaffold also formed mineralized nodules.

Abstract: Electron beam melting (EBM) has been recognized as a revolutionary manufacturing process. This layer-by-layer additive manufacturing process has shown great promise for fabrication of biomedical implants and aerospace components. This paper represents an investigation into the particle size distribution, morphology and flow-ability of Ti6Al4V powder used in EBM process. The effect of recycling of the powder on the chemical properties has been investigated. Results show that recycling increases the weight percentage of interstitial elements. The flow-ability and apparent density of the powder were measured before and after recycling process and no change was observed.

Abstract: Electron beam melting (EBM) is a direct metal additive manufacturing technique in which a 4 kW electron beam is utilized to manufacture the parts in a layer by layer fashion. This paper represents an investigation into the quasi-static compressive deformation behavior of EBM made specimens. The mechanical testing was carried out at strain rate of 10^-3 s^-1 by a numerically controlled hydraulic MTS machine on both as-built and machined samples manufactured by this high-tech process. The Vickers micro-hardness of the samples has been measured before and after the compression test. The microstructure of the compressed sample was characterized. The particle size distribution, morphology, and chemical composition of the Ti6Al4V, which is one of the most common materials for biomedical implants because of its high strength to weight ratio, corrosion resistance, and its biocompatibility features, have been investigated. The fracture surface has been characterized by scanning electron microscope.

Abstract: Electron beam melting (EBM) method is one of the free-form fabrication techniques that enable near-net-shape manufacturing of complex three-dimensional, porous, and graded products, and is expected to facilitate the development of new methods for manufacturing biomaterials that could be used for hard-tissue substitutes. Titanium and its alloys have been used widely as biomaterials for hard-tissue substitutes because of their excellent mechanical properties and biocompatibility. However, the osteointegration of these materials is less than that of bioactive ceramics. Therefore, various surface-modification techniques have been developed to improve the osteointegration. The simplest way is to synthesize bioactive ceramic films on the surface of titanium or its alloys. The purpose of the present work was to synthesize a bioactive TiO₂ film on Ti-6Al-4V (hereafter, abbreviated as Ti-64) substrates fabricated from powders using the EBM method and treated by a combination of chemical and hydrothermal treatment. Ti-64 plates fabricated by the EBM method were chemically treated with a H₂O₂/HNO₃ aqueous solution under appropriate conditions. The plates were then hydrothermally treated with a NH₃ aqueous solution. TiO₂-gel films were produced by chemical treatment with a H₂O₂/HNO₃ aqueous solution on the surface of a Ti-64 substrate. Anatase-type TiO₂ films with high crystallinity were synthesized by the hydrothermal treatment of the TiO₂-gel films.

Abstract: The simulation of residual stress in Electron Beam Melting (EBM) process is critical for optimization of process conditions. However, there is no published literature on the simulation of residual stresses in this process. This paper considers finite element modeling of the temperature distribution through transient thermal analysis. The measured temperature and total heat flux from transient thermal analysis are then used as initial input parameters to the structural analysis. Consequently, deformations and residual stresses in structural analysis were measured. The titanium alloy, Ti6Al4V has been used, which is one of the most common materials for biomedical implants due to its high strength to weight ratio, corrosion resistance, and its biocompatibility features.

Abstract: Electron beam melting (EBM) is a direct metal additive manufacturing technique which has been recently utilized for fabrication of biomedical implants. This paper represents an investigation into the mechanical properties of both as-built and hot isostatic pressing (HIP) processed samples manufactured in EBM process. The titanium alloy, Ti6Al4V was used, which is one of the most common materials for biomedical implants due to its high strength to weight ratio, corrosion resistance, and its biocompatibility features. Tensile properties, surface roughness, and Vickers microhardness have been investigated.