Properties of Test Coupons Fabricated by Selective Laser Melting

2010 ◽  
Vol 447-448 ◽  
pp. 780-784 ◽  
Author(s):  
A. Liu ◽  
Chee Kai Chua ◽  
Kah Fai Leong
Keyword(s):  
Surface Roughness ◽  
Selective Laser Melting ◽  
Fibre Laser ◽  
Fibre Lasers ◽  
Laser Melting ◽  
Superior Result ◽  
Heat Treated ◽  
Diode Pumped ◽  
Part Density ◽  
Better Than

Selective Laser Melting (SLM) is a popular and promising Additive Manufacturing (AM) technique as it can produce parts with complex internal features with part density close to 100%. However, unprocessed raw SLM fabricated parts have surface roughness issues and the mechanical properties of raw SLM parts without heat treatment are not ideal. The material used to address some of these issues in this research is an Aluminum alloy, AlSi10Mg – a strong and light weight metal. The SLM machine engaged for the test coupons fabrication is M2 Cusing from Concept Laser, Germany, which uses a diode pumped Yb-Fibre laser (Ytterbium-doped fibre lasers) with an effective output power of 200W. It is found that SLM fabricated parts with and without sandblasting shows up to 80% difference in surface roughness values. Also, the tensile test experiments of raw untreated SLM parts carried out at room temperature and at high temperature (200oC) show superior result compared with heat treated casted parts. Other properties such as hardness and density (porosity) are found to be better than heat treated cast parts as well.

scholarly journals Studying the Microstructural Effect of Selective Laser Melting and Electropolishing on the Performance of Maraging Steel

2021 ◽  
Author(s):  
D. Ahmadkhaniha ◽  
H. Möller ◽  
C. Zanella
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Maraging Steel ◽  
Selective Laser Melting ◽  
Cross Section ◽  
Corrosion Behavior ◽  
Main Role ◽  
Laser Melting ◽  
Heat Treated ◽  
Manufacturing Technologies

AbstractSelective laser melting is one of the additive manufacturing technologies that have been known for building various and complicated shapes. Despite numerous advantages of additive manufacturing technologies, they strongly influence the microstructure and typically show a relatively high surface roughness. In this study, maraging steel was produced by selective laser melting (SLM), and its microstructure, hardness and corrosion behavior before and after heat treatment were studied and compared to traditionally manufactured ones (wrought, forged samples). In addition, the effect of electropolishing on the surface roughness was evaluated. The microstructural study was carried out by scanning electron microscopy equipped with electron backscattered diffraction in three different sections: parallel to the top surface (xy), transverse cross section (xz) and longitudinal cross section (yz). The same characterization was applied to heat-treated samples, austenitized and quenched as well as the aged ones. The results showed that selective laser melting produced a fine grain martensitic structure (in the as-printed condition) with a surface roughness (Ra) of about 10 µm. There was no sign of preferred texture or anisotropy in the microstructure of as-print SLM materials. The SLM microstructure was similar in all 3 sections (xy, xz and yz). Despite finer microstructure, nano-hardness and corrosion behavior of SLM and conventional wrought maraging steel in heat-treated conditions were similar. Aging resulted in the maximum nano-hardness and the minimum corrosion potential values. Precipitation has the main role in both hardness and corrosion behavior. Electropolishing was optimized and reduced the surface roughness (Ra) by 65%.

scholarly journals Improving surface quality in selective laser melting based tool making

2021 ◽  
Author(s):  
Filippo Simoni ◽  
Andrea Huxol ◽  
Franz-Josef Villmer
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Surface Quality ◽  
Selective Laser Melting ◽  
Melting Process ◽  
Laser Remelting ◽  
Laser Melting ◽  
Great Cost ◽  
Starting Point ◽  
Processing Techniques

AbstractIn the last years, Additive Manufacturing, thanks to its capability of continuous improvements in performance and cost-efficiency, was able to partly replace and redefine well-established manufacturing processes. This research is based on the idea to achieve great cost and operational benefits especially in the field of tool making for injection molding by combining traditional and additive manufacturing in one process chain. Special attention is given to the surface quality in terms of surface roughness and its optimization directly in the Selective Laser Melting process. This article presents the possibility for a remelting process of the SLM parts as a way to optimize the surfaces of the produced parts. The influence of laser remelting on the surface roughness of the parts is analyzed while varying machine parameters like laser power and scan settings. Laser remelting with optimized parameter settings considerably improves the surface quality of SLM parts and is a great starting point for further post-processing techniques, which require a low initial value of surface roughness.

scholarly journals Directionally-Dependent Mechanical Properties of Ti6Al4V Manufactured by Electron Beam Melting (EBM) and Selective Laser Melting (SLM)

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3603
Author(s):  
Tim Pasang ◽  
Benny Tavlovich ◽  
Omry Yannay ◽  
Ben Jakson ◽  
Mike Fry ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Electron Beam Melting ◽  
Rolling Direction ◽  
Laser Melting ◽  
Plate Rolling

An investigation of mechanical properties of Ti6Al4V produced by additive manufacturing (AM) in the as-printed condition have been conducted and compared with wrought alloys. The AM samples were built by Selective Laser Melting (SLM) and Electron Beam Melting (EBM) in 0°, 45° and 90°—relative to horizontal direction. Similarly, the wrought samples were also cut and tested in the same directions relative to the plate rolling direction. The microstructures of the samples were significantly different on all samples. α′ martensite was observed on the SLM, acicular α on EBM and combination of both on the wrought alloy. EBM samples had higher surface roughness (Ra) compared with both SLM and wrought alloy. SLM samples were comparatively harder than wrought alloy and EBM. Tensile strength of the wrought alloy was higher in all directions except for 45°, where SLM samples showed higher strength than both EBM and wrought alloy on that direction. The ductility of the wrought alloy was consistently higher than both SLM and EBM indicated by clear necking feature on the wrought alloy samples. Dimples were observed on all fracture surfaces.

Assessment of Heat Treatment Effect on AlSi10Mg by Selective Laser Melting through Indentation Testing

2019 ◽  
Vol 813 ◽  
pp. 171-177 ◽  
Author(s):  
Giacomo Maculotti ◽  
Gianfranco Genta ◽  
Massimo Lorusso ◽  
Maurizio Galetto
Keyword(s):  
Selective Laser Melting ◽  
Melt Spinning ◽  
Ad Hoc ◽  
Indentation Test ◽  
Al Alloy ◽  
Laser Melting ◽  
Heat Treated ◽  
Processing Properties ◽  
Am Processes ◽  
Metal Additive

Selective Laser Melting (SLM) is one of the leader metal Additive Manufacturing (AM) processes thanks to its capability of coupling freeform design and environmental and economical sustainability to high mechanical properties. AlSi10Mg is a light weight Al-alloy with interesting processing properties and enhanced strength thanks to the presence of Mg, which, hence, finds application in several industrial fields. Furthermore, SLM allows overcoming those design constraints set by casting and melt spinning; however, SLM AlSi10Mg components require to be heat treated, both to strengthen the material and to engineer the microstructure. In this work, in order to assess the effectiveness of heat treatments on AlSi10Mg by SLM, an ad hoc analysis procedure based on statistical tools is applied in combination with indentation characterisation tests. In particular, to achieve full scale characterisation, traditional Brinell hardness and Instrumented Indentation Test (IIT) in macro and nano-range are considered. In particular, IIT is applied both at the lower end of macro range to provide consistency and statistically investigate relationship with Brinell scale and in the nano-range, enabling local, i.e. grain, and surface properties to be characterised.

scholarly journals Selective laser melting for improving quality characteristics of a prism shaped topology injection mould tool insert for the automotive industry

2021 ◽  
pp. 095440622198938
Author(s):  
Mennatallah F El Kashouty ◽  
Allan EW Rennie ◽  
Mootaz Ghazy ◽  
Ahmed Abd El Aziz
Keyword(s):  
Surface Roughness ◽  
Selective Laser Melting ◽  
Automotive Industry ◽  
Injection Moulding ◽  
Dimensional Accuracy ◽  
Quality Characteristics ◽  
Surface Topology ◽  
Laser Melting ◽  
Injection Mould ◽  
Tool Insert

Manufacturing process constraints and design complexities are the main challenges that face the aftermarket automotive industry. For that reason, recently, selective laser melting (SLM) is being recognised as a viable approach in the fabrication of injection moulding tool inserts. Due to its versatility, SLM technology is capable of producing freeform designs. For the first reported time, in this study SLM is recognized for its novel application in overcoming fabrication complexities for prism shaped topology of a vehicle headlamp’s reflector injection moulding tool insert. Henceforth, performance measures of the SLM-fabricated injection mould tool insert is assessed in comparison to a CNC-milled counterpart to improve quality characteristics. Tests executed and detailed in this paper are divided into two stages; the first stage assesses both fabricated tool inserts in terms of manufacturability; the second stage assesses the functionality of the end-products by measuring the surface roughness, dimensional accuracy and light reflectivity from the vehicle reflectors. The results obtained show that employing SLM technology can offer an effective and efficient alternative to subtractive manufacturing, successfully producing tool inserts with complex surface topology. Significant benefits in terms of surface roughness, dimensional accuracy and product functionality were achieved through the use of SLM technology. it was concluded that the SLM-fabricated inserts products proved to have relatively lower values of surface roughness in comparison to their CNC counterparts.

Effect of laser rescanning on Ti6Al4V microstructure during selective laser melting

2020 ◽  
pp. 095440542097609
Author(s):  
Weipeng Duan ◽  
Meiping Wu ◽  
Jitai Han
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Selective Laser Melting ◽  
Human Body ◽  
High Impact ◽  
Laser Melting ◽  
Heat Treated ◽  
Volume Porosity ◽  
Biomedical Field

TC4, which is one of the most widely used titanium alloy, is frequently used in biomedical field due to its biocompatible. In this work, selective laser melting (SLM) was used to manufacture TC4 parts and the printed parts were heat-treated using laser rescanning technology. The experimental results showed that laser rescanning had a high impact on the quality of SLMed part, and a different performance on wear resistance can be found on the basis. It can be seen that the volume porosity of the sample was 7.6 ± 0.5% without using any further processing technology. The volume porosity of the sample processed using laser rescanning strategy was decreased and the square-framed rescanning strategy had a relative optimal volume porosity (1.5 ± 0.3%) in all these five samples. With the further decreasing of volume porosity, the wear resistance decreased at the same time. As its excellent bio-tribological properties, the square-framed rescanning may be a potential suitable strategy to forming TC4 which used in human body.

scholarly journals Investigation on Selective Laser Melting AlSi10Mg Cellular Lattice Strut: Molten Pool Morphology, Surface Roughness and Dimensional Accuracy

Materials ◽  
2018 ◽  
Vol 11 (3) ◽  
pp. 392 ◽  
Author(s):  
Xuesong Han ◽  
Haihong Zhu ◽  
Xiaojia Nie ◽  
Guoqing Wang ◽  
Xiaoyan Zeng
Keyword(s):  
Surface Roughness ◽  
Selective Laser Melting ◽  
Molten Pool ◽  
Dimensional Accuracy ◽  
Laser Melting

Mechanical Behaviour of Gas Nitrided Ti6Al4V Bars Produced by Selective Laser Melting

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Nitrided Layer ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Processing Parameters ◽  
Heat Treatments ◽  
Laser Melting ◽  
Gas Nitriding ◽  
Heat Treated

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.

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