scholarly journals Analysis of Modern Optical Inspection Systems for Parts Manufactured by Selective Laser Melting

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3202
Author(s):  
Sara Giganto ◽  
Susana Martínez-Pellitero ◽  
Eduardo Cuesta ◽  
Víctor M. Meana ◽  
Joaquín Barreiro
Keyword(s):  
Selective Laser Melting ◽  
Optical Measurement ◽  
Point Of View ◽  
Laser Triangulation ◽  
Laser Melting ◽  
Measurement Systems ◽  
Geometric Dimensioning And Tolerancing ◽  
Inspection Systems ◽  
Conoscopic Holography ◽  
T Values

Metal additive manufacturing (AM) allows obtaining functional parts with the possibility of optimizing them topologically without affecting system performance. This is of great interest for sectors such as aerospace, automotive, and medical–surgical. However, from a metrological point of view, the high requirements applied in these sectors constitute a challenge for inspecting these types of parts. Non-contact inspection has gained great relevance due to the rapid verification of AM parts. Optical measurement systems (OMSs) are being increasingly adopted for geometric dimensioning and tolerancing (GD&T) verification within the context of Industry 4.0. In this paper, the suitability (advantages and limitations) of five different OMSs (based on laser triangulation, conoscopic holography, and structured light techniques) for GD&T verification of parts manufactured by selective laser melting (SLM) is analyzed. For this purpose, a specific testing part was designed and SLM-manufactured in 17-4PH stainless steel. Once the part was measured by contact (obtaining the reference GD&T values), it was optically measured. The scanning results allow comparing the OMSs in terms of their inspection speed as well as dimensional and geometrical accuracy. As a result, two portable systems (handheld laser triangulation and structured blue-light scanners) were identified as the most accurate optical techniques for scanning SLM parts.

scholarly journals Selective laser melting of Ti6Al7Nb with hydroxyapatite addition

2014 ◽  
Vol 20 (4) ◽  
pp. 301-310 ◽  
Author(s):  
Teodora Marcu ◽  
Cinzia Menapace ◽  
Luca Girardini ◽  
Dan Leordean ◽  
Catalin Popa
Keyword(s):  
Selective Laser Melting ◽  
Laser Power ◽  
Design Methodology ◽  
Point Of View ◽  
Medical Applications ◽  
Laser Melting ◽  
Scanning Strategy ◽  
Content Type ◽  
Processing Times ◽  
Scanning Electron

Purpose – The purpose of this paper was to obtain by means of selective laser melting and then characterize biocomposites of medical-grade Ti6Al7Nb with hydroxyapatite (2 and 5 vol.%) and without hydroxyapatite, as reference. Design/methodology/approach – Rectangular samples were manufactured with the same scanning strategy; the laser power was between 50 W and 200 W. Processed samples were analysed by means of optical microscopy, scanning electron microscopy and microhardness. Findings – The results showed that despite the very short processing times, hydroxyapatite decomposed and interacted with the base Ti6Al7Nb material. The decomposition degree was found to depend on the applied laser power. From the porosity and bulk microstructure point of view, the most appropriate materials for the purposed medical applications were Ti6Al7Nb with hydroxyapatite processed with a laser power of 50 W. Originality/value – The originality of the present work consists in the study of the behaviour and interaction of hydroxyapatite additive with the Ti6Al7Nb base powder under selective laser melting conditions, as depending on the applied laser power.

Finite Element Analysis to Predict the Mechanical Behavior of Lattice Structures Made by Selective Laser Melting Technology

2014 ◽  
Vol 657 ◽  
pp. 231-235 ◽  
Author(s):  
Răzvan Păcurar ◽  
Ancuţa Păcurar ◽  
Anna Petrilak ◽  
Nicolae Bâlc
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Selective Laser Melting ◽  
Lattice Structure ◽  
Point Of View ◽  
Mechanical Resistance ◽  
Lattice Structures ◽  
Laser Melting ◽  
Element Analysis ◽  
Medical Implant

Within this article, there are presented a series of researches that are related to the field of customized medical implants made by Additive Manufacturing techniques, such as Selective Laser Melting (SLM) technology. Lattice structures are required in this case for a better osteointegration of the medical implant in the contact area of the bone. But the consequence of using such structures is important also by the mechanical resistance point of view. The shape and size of the cells that are connected within the lattice structure to be manufactured by SLM is critical in this case. There are also few limitations related to the possibilities and performances of the SLM equipment, as well. This is the reason why, several types of lattice structures were designed as having different geometric features, with the aim of analyzing by using finite element method, how the admissible stress and strain will be varied in these cases and what would be the optimum size and shape of the cells that confers the optimum mechanical behavior of lattice structures used within the SLM process of the customized medical implant manufactured from titanium-alloyed materials.

Analysis of post-processing influence on the geometrical and dimensional accuracy of selective laser melting parts

2020 ◽  
Vol 26 (10) ◽  
pp. 1713-1722
Author(s):  
Eduardo Cuesta ◽  
Braulio J. Alvarez ◽  
Pablo Zapico ◽  
Sara Giganto
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Point Of View ◽  
Laser Melting ◽  
Sand Blasting ◽  
Content Type ◽  
Stress Relieving ◽  
Measuring Machine

Purpose This study aims to analyze the effect of the different common post-processes on the geometrical and dimensional accuracy of selective laser melting (SLM) parts. Design/methodology/approach An artefact has been designed including cubic features formed by planar surfaces orientated according to the machine axes, covering all the X-Y area of the working space. The artefact has been analyzed both geometrically (flatness, parallelism) and dimensionally (sizes, distances) from coordinate measuring machine measurement results at three stages, namely, as-built, after sand-blasting and after stress-relieving heat treatment. Findings Results from the SLM machine used in this study lead to smaller parts than the nominal ones. This effect depends on the direction of the evaluated dimension of the parts, i.e. X, Y or Z direction and is differently affected by the sandblasting post-process (average erosion ratio of 68, 54 and 9 µm, respectively), being practically unaltered by the HT applied after. Originality/value This paper shows the influence, from a geometric and dimensional point of view, of two of the most common post-processes used after producing SLM parts, such as sand-blasting and stress-relieving heat treatment, that have not been considered in previous research.

Technological Limitations of Selective Laser Melting Method

2015 ◽  
Vol 752-753 ◽  
pp. 878-883 ◽  
Author(s):  
Tatiana Tarasova ◽  
Alexey Nazarov
Keyword(s):  
Selective Laser Melting ◽  
High Precision ◽  
Point Of View ◽  
Technological Capabilities ◽  
Cobalt Alloy ◽  
Laser Melting ◽  
Melting Method ◽  
Technological Limitations

The method of selective laser melting (further SLM) has big prospects from the point of view of achievement of a difficult form of details with high precision and quality of a surface, however SLM has also a number of technological restrictions from the point of view of achievement of a difficult form of details. In this work technological capabilities of production of figurine details from a heat resisting cobalt alloy are investigated by method of selective laser melting, technological restrictions of a method and way of their overcoming are shown.

Sensor-Realistic Simulations for Evaluation and Planning of Optical Measurement Systems With an Application to Laser Triangulation

2020 ◽  
Vol 20 (10) ◽  
pp. 5336-5349
Author(s):  
Mahsa Mohammadikaji ◽  
Stephan Bergmann ◽  
Jurgen Beyerer ◽  
Jan Burke ◽  
Carsten Dachsbacher
Keyword(s):  
Optical Measurement ◽  
Laser Triangulation ◽  
Measurement Systems

Topology Optimization of an Airplane Component to Be Made by Selective Laser Melting Technology

2015 ◽  
Vol 808 ◽  
pp. 181-186
Author(s):  
Răzvan Păcurar ◽  
Ancuţa Păcurar
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Mechanical Strength ◽  
Mechanical Behavior ◽  
Selective Laser Melting ◽  
Minimum Weight ◽  
Point Of View ◽  
Laser Melting ◽  
Optimization Program ◽  
Airplane Fuselage

This paper presents a research performed in the field of airplane components made by Additive Manufacturing (AM) methods, such as Selective Laser Melting (SLM) technology. The mechanical behavior of fixing clamps for the hydraulic pipes that are passing through an airplane fuselage has been analyzed by using a dedicated topology optimization program. Two types of materials have been considered as an alternative for this type of component to be manufactured by SLM: Ti6Al4V and AlSi12. By using the Femap NX Nastran topology optimization program, it was possible to re-design the shape of this component and to select the best type of material that is adequate from the mechanical strength point of view, with a minimum weight as an optimization goal.

MANUFACTURING NOVEL HEAT TRANSFER DEVICES BY SELECTIVE LASER MELTING

Equipment ◽  
2006 ◽  
Author(s):  
S. Tsopanos ◽  
M. Wong ◽  
I. Owen ◽  
C. J. Sutcliffe
Keyword(s):  
Heat Transfer ◽  
Selective Laser Melting ◽  
Laser Melting

Properties of Ti-6Al-4V titanium alloys obtained by selective laser melting

2019 ◽  
pp. 46-57
Author(s):  
M.A. Kaplan ◽  
◽  
М.A. Smirnov ◽  
A.A. Kirsankin ◽  
M.A. Sevostyanov ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Selective Laser Melting ◽  
Laser Melting
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