Selective laser melting of elemental powder blends for fabrication of homogeneous bulk material of near-eutectic Ni‒Sn composition

2020 ◽  
Vol 34 ◽  
pp. 101261
Author(s):  
Rijie Zhao ◽  
Jianrong Gao ◽  
Hanlin Liao ◽  
Nouredine Fenineche ◽  
Christian Coddet
Keyword(s):  
Selective Laser Melting ◽  
Bulk Material ◽  
Elemental Powder ◽  
Laser Melting ◽  
Powder Blends

scholarly journals Nanoscale chemistry and atomic-scale microstructure of a bulk Ni3Sn material built using selective laser melting of elemental powder blends

2021 ◽  
pp. 110152
Author(s):  
Rijie Zhao ◽  
Tingting Yang ◽  
Hanlin Liao ◽  
Nouredine Fenineche ◽  
Christian Coddet ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Atomic Scale ◽  
Elemental Powder ◽  
Laser Melting ◽  
Powder Blends

scholarly journals Microstructural and Mechanical Response of NiTi Lattice 3D Structure Produced by Selective Laser Melting

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 814 ◽  
Author(s):  
Carlo Alberto Biffi ◽  
Paola Bassani ◽  
Jacopo Fiocchi ◽  
Ausonio Tuissi
Keyword(s):  
Martensitic Transformation ◽  
Selective Laser Melting ◽  
Mechanical Response ◽  
Electron Backscatter Diffraction ◽  
Bulk Material ◽  
Niti Alloy ◽  
3D Structure ◽  
Lattice Structures ◽  
Laser Melting ◽  
Scanning Calorimetry

Nowadays, additive manufacturing (AM) permits to realize complex metallic structural parts, and the use of NiTi alloy, known as Nitinol, allows the integration of specific functions to the AM products. One of the most promising designs for AM is concerning the use of lattice structures that show lightweight, higher than bulk material deformability, improved damping properties, high exchange surface. Moreover, lattice structures can be realized with struts, having dimensions below 1 mm—this is very attractive for the realization of Nitinol components for biomedical devices. In this light, the present work regarded the experimental characterization of lattice structures, produced by selective laser melting (SLM), by using Ni-rich NiTi alloy. Differential scanning calorimetry (DSC), electron backscatter diffraction (EBSD), and compression testing were carried out for analyzing microstructure, martensitic transformation (MT) evolution, and superelasticity response of the SLMed lattice samples. The lattice microstructures were compared with those of the SLMed bulk material for highlighting differences. Localized martensite was detected in the nodes zones, where the rapid solidification tends to accumulate solidification stresses. An increase of martensitic transformation temperatures was also observed in lattice NiTi.

Manufacturing of Porous Biomaterials for Dental Implant Applications through Selective Laser Melting

2012 ◽  
Vol 535-537 ◽  
pp. 1222-1229 ◽  
Author(s):  
Francesco Cardaropoli ◽  
Vittorio Alfieri ◽  
Fabrizia Caiazzo ◽  
Vincenzo Sergi
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Dental Implants ◽  
Selective Laser Melting ◽  
Young's Modulus ◽  
Bulk Material ◽  
Total Porosity ◽  
Porous Metals ◽  
Efficient Technology ◽  
Laser Melting

The paper discusses the possibility of manufacturing dental implants through Selective Laser Melting (SLM) of a Ti-6Al-4V alloy powder. Among all possible biomaterials, this alloy is widely used in biomedical applications due to high biocompatibility. Selective Laser Melting allows to obtain biomaterials with peculiar characteristics in terms of porosity gradient, roughness, customized geometry, and mechanical properties. Influence of input process parameters on porosity and analysis of Selective Laser Melting capabilities in implant dentistry have been focused. Porosity is a key parameter in dental implants as it affects stiffness, which is related to Young’s modulus. Ti-6Al-4V bulk material presents a Young’s modulus of 110 GPa, whereas the bone one ranges from 10 to 26 GPa. The relative difference of mechanical properties causes the phenomenon of stress shielding, which has a detrimental effect on the longevity of dental implants. Total porosity is important in reducing the effective modulus of porous metals. Biomaterials specimens obtained during experimental phase have been examined in terms of porosity (in inverse ratio to relative density), microstructure, microhardness and roughness. According to test results discussed in this paper, Selective Laser Melting is proved to be an efficient technology for the construction of Ti-6Al-4V dental implants, because biomaterials with adequate properties can be obtained changing processing parameters. Other fabrication techniques fail to produce biomaterials for dental implants with the desired features.

Effect of build orientation on fracture behaviour of AlSi10Mg produced by selective laser melting

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sultan AlRedha ◽  
Anton Shterenlikht ◽  
Mahmoud Mostafavi ◽  
Derreck Van Gelderen ◽  
Omar Eduardo Lopez-Botello ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Selective Laser Melting ◽  
Grain Orientation ◽  
Mechanical Performance ◽  
Bulk Material ◽  
Laser Melting ◽  
Content Type ◽  
Build Orientation ◽  
Melt Pool ◽  
Melting Pool

Purpose A key challenge found in additive manufacturing is the difficulty to produce components with replicable microstructure and mechanical performance in distinct orientations. This study aims to investigate the influence of build orientation on the fracture toughness of additively manufactured AlSi10Mg specimens. Design/methodology/approach The AlSi10Mg specimens were manufactured using the selective laser melting (SLM) technology. The fracture toughness was experimentally determined (under ASTM E399-09) using C(T) specimens manufactured in different orientations. The microstructure of the specimens was examined using metallography to determine the effects of grain orientation on fracture toughness. Findings The fracture toughness magnitude of manufactured specimens ranged between 36 and 50 MPam, which closely matched conventional bulk material and literature values regarding AlSi10Mg components. The C(T) specimens printed in the T-L orientation yielded the highest fracture toughness. The grain orientation and fracture toughness values confirm the anisotropic nature of SLM parts where the T-L-oriented specimen obtained the highest KIC value. A clear interaction between the melt pool boundaries and micro-slipping during the loading application was observed. Originality/value The novelty of this paper consists in elucidating the relationship between grain orientation and fracture toughness of additively manufactured AlSi10Mg specimens because of the anisotropy generated by the different melting pool boundaries and orientations in SLM. The findings show that melt pool boundaries can behave as easier pathways for cracks to propagate and subsequently reduce the fracture toughness of specimens with cracks perpendicular to the build direction.

Investigation of Ti-6Al-4V Alloy In Situ Manufactured Using Selective Laser Melting from Elemental Powder Mixture

2020 ◽  
Vol 299 ◽  
pp. 646-651
Author(s):  
Igor Polozov ◽  
Vadim Sufiiarov ◽  
Anatoliy Popovich
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Powder Mixture ◽  
Elemental Powder ◽  
Laser Melting ◽  
Before And After ◽  
Elemental Powder Mixture ◽  
The Difference

This paper presents the results of the study of Selective Laser Melting (SLM) process for the in-situ synthesis of Ti-6Al-4V alloy from elemental powder mixture. Elemental spherical powders of Ti, Al and V were used to prepare a powder mixture, and then bulk specimens were produced by SLM using different process parameters. The effects of SLM process parameters on samples’ relative density, their chemical composition, the formed microstructure and microhardness before and after heat treatment have been studied. It was shown that volume energy density during the SLM process significantly effects the microstructure and microhardness of Ti-6Al-4V obtained from elemental powders. The difference in microstructure morphology and microhardness remains after heat treatment.

scholarly journals Fabricating Homogeneous FeCoCrNi High-Entropy Alloys via SLM In Situ Alloying

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 942
Author(s):  
Yaqing Hou ◽  
Hang Su ◽  
Hao Zhang ◽  
Xuandong Wang ◽  
Changchang Wang
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Traditional Method ◽  
Raw Material ◽  
Elemental Powder ◽  
High Entropy Alloys ◽  
Laser Melting ◽  
High Entropy ◽  
Powder Blend

Selective laser melting (SLM) in situ alloying is an effective way to design and fabricate novel materials in which the elemental powder is adopted as the raw material and micro-areas of elemental powder blend are alloyed synchronously in the forming process of selective laser melting (SLM). The pre-alloying process of preparation of raw material powder can be left out, and a batch of bulk samples can be prepared via the technology combined with quantitative powder mixing and feeding. The technique can be applied to high-throughput sample preparation to efficiently obtain a microstructure and performance data for material design. In the present work, bulk equiatomic FeCoCrNi high-entropy alloys with different processing parameters were fabricated via laser in situ alloying. Finite element simulation and CALPHAD calculation were used to determine the appropriate SLM and post-heating parameters. SEM (scanning electron microscope), EDS (energy dispersive spectroscopy), XRD (X-ray diffraction), and mechanical testing were used to characterize the composition, microstructure, and mechanical properties of as-printed and post-heat-treated samples. The experimental results show that the composition deviation of laser in situ alloying samples could be controlled within 20 wt %. The crystal structure of as-printed samples is a single-phase face-centered cubic (FCC), which is the same as those prepared by the traditional method. The mechanical properties of the samples prepared by laser in situ alloying with elemental powder blend are comparable to those prepared by pre-alloying powder and much higher than those prepared by the traditional method (arc melting). As-printed samples can get a homogeneous microstructure under the optimal laser in situ alloying process combined with post-heat treatment at 1200 °C for 20 h.

scholarly journals Meso-scale defect evaluation of selective laser melting using spatially resolved acoustic spectroscopy

2017 ◽  
Vol 473 (2205) ◽  
pp. 20170194 ◽  
Author(s):  
M. Hirsch ◽  
S. Catchpole-Smith ◽  
R. Patel ◽  
P. Marrow ◽  
Wenqi Li ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Power Plants ◽  
Surface Defects ◽  
Defect Density ◽  
Bulk Material ◽  
Density Measurement ◽  
Nickel Superalloy ◽  
Laser Melting ◽  
Spatially Resolved ◽  
Acoustic Spectroscopy

Developments in additive manufacturing technology are serving to expand the potential applications. Critical developments are required in the supporting areas of measurement and in process inspection to achieve this. CM247LC is a nickel superalloy that is of interest for use in aerospace and civil power plants. However, it is difficult to process via selective laser melting (SLM) as it suffers from cracking during rapid cooling and solidification. This limits the viability of CM247LC parts created using SLM. To quantify part integrity, spatially resolved acoustic spectroscopy (SRAS) has been identified as a viable non-destructive evaluation technique. In this study, a combination of optical microscopy and SRAS was used to identify and classify the surface defects present in SLM-produced parts. By analysing the datasets and scan trajectories, it is possible to correlate morphological information with process parameters. Image processing was used to quantify porosity and cracking for bulk density measurement. Analysis of surface acoustic wave data showed that an error in manufacture in the form of an overscan occurred. Comparing areas affected by overscan with a bulk material, a change in defect density from 1.17% in the bulk material to 5.32% in the overscan regions was observed, highlighting the need to reduce overscan areas in manufacture.

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