Microstructure and Properties of Laser-Selected Melt-Formed AlSi10Mg Alloy

2021 ◽  
Vol 1035 ◽  
pp. 51-56
Author(s):  
Ran Liu ◽  
Yuan Gao ◽  
Si Jie Zhang
Keyword(s):  
Laser Power ◽  
Laser Scanning ◽  
Heat Dissipation ◽  
Laser Energy ◽  
Growth Direction ◽  
Fish Scale ◽  
Laser Melting ◽  
Eutectic Si ◽  
Microstructure Density ◽  
Component Direction

The AlSi10Mg alloy samples were prepared by laser selective melting technology, and the effects of laser power, scanning distance and powder thickness on the microstructure, density and mechanical properties of the formed AlSi10Mg alloy samples were studied. The results showed that the phases of the AlSi10Mg alloy formed by laser melting in the selected area are mainly α-Al matrix and eutectic Si; the forming parallel to the direction of the component forms a typical fish scale structure, which is formed after the laser scanning molten pool solidifies , Its growth direction is parallel to the direction of heat dissipation; as the laser energy density decreases, the height of the fish scale tissue decreases and the width increases; when the laser power is higher, the density of the formed sample is also higher; the laser power is 900W, The sample with a scanning distance of 0.09mm and a spreading thickness of 0.05mm has better performance. The tensile strength and elongation of the sample parallel to the component direction are 288MPa and 2.1%, respectively.

Selective Laser Melting of Mechanically Alloyed Metastable Al5Fe2 Powders

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Hugo Montiel ◽  
Ben Xu ◽  
Jianzhi Li
Keyword(s):  
Aluminum Alloys ◽  
Energy Density ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
Laser Energy ◽  
Scanning Speed ◽  
High Energy ◽  
Laser Energy Density ◽  
Laser Melting

Aluminum alloys, which are high-strength lightweight materials, were processed by selective laser melting (SLM) with high-energy consumption and poor finish due to quick heat dissipation. Previous investigations reported that SLM with 300 W laser power and 500 mm/s scanning speed can process the aluminum alloys, such as Al-Si12 and AlSi10Mg. This work aims to process the powders to alter their properties and to reduce the laser intensity required in the process, and it also reports that the SLM-processed Al–Fe alloys utilize the metastable alloy by mechanical alloying (MA). The elemental Al and Fe powders were first alloyed in a ball mill in a relative short time period (∼15 h) employing high milling intensities, high ball-to-powder ratio (≥20:1), and high milling velocities (≥400 rpm), which produced fine metastable Al–Fe powders, and these powders were processed later by the SLM. The optimum laser power, the scanning speed, hatch distance, and substrate temperature were investigated by a series of experiments. Experimental results indicated that decreasing the laser energy density while increasing the laser scanning speed can benefit for smoother laser hatch lines, and the metastable Al5Fe2 alloy powders can be processed and stabilized under a 200-W laser energy density and a scanning speed of 1000 mm/s. It is expected that the combination of pre-excited materials in a metastable phase will open a new window to optimize the SLM process for aluminum alloys and other metallic alloys.

scholarly journals Influence of Material Property Variation on Computationally Calculated Melt Pool Temperature during Laser Melting Process

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 456 ◽  
Author(s):  
Sazzad H. Ahmed ◽  
Ahsan Mian
Keyword(s):  
Thermal Conductivity ◽  
Specific Heat ◽  
Process Parameters ◽  
Laser Power ◽  
Laser Scanning ◽  
Peak Temperature ◽  
Powder Layer ◽  
Laser Melting ◽  
Melt Pool ◽  
Melt Pool Temperature

Selective Laser Melting (SLM) is a popular additive manufacturing (AM) method where a laser beam selectively melts powder layer by layer based on the building geometry. The melt pool peak temperature during build process is an important parameter to determine build quality of a fabricated component by SLM process. The melt pool temperature depends on process parameters including laser power, scanning speed, and hatch space as well as the properties of the build material. In this paper, the sensitivity of melt pool peak temperature during the build process to temperature dependent material properties including density, specific heat, and thermal conductivity are investigated for a range of laser powers and laser scanning speeds. It is observed that the melt pool temperature is most sensitive to melt pool thermal conductivity of the processed material for a set of specific process parameters (e.g., laser power and scan speed). Variations in the other mechanical–physical properties of powder and melt pool such as density and specific heat are found to have minimal effect on melt pool temperature.

Thermal Modeling of 304L Stainless Steel for Selective Laser Melting: Laser Power Input Evaluation

2017 ◽  
Author(s):  
Diego Augusto de Moraes ◽  
Aleksander Czekanski
Keyword(s):  
Stainless Steel ◽  
Temperature Distribution ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
Power Input ◽  
304L Stainless Steel ◽  
Laser Melting ◽  
Powder Bed ◽  
The Impact

Selective Laser Melting (SLM) process is a Powder Bed Fusion (PBF) technique, which has shown significantly growth in the recent years. The demand for this process is justified by the versatility and ease in manufacturing the parts from 3D models as well for the increased complexity of engineered parts generated from topology or shape optimization. Automotive, aerospace, medical and aviation industries are taking great advantage of this process due the unique geometry characteristics found in the components. To enhance the benefits of SLM, a vital task is to analyze the laser power input impact on the temperature distribution through the powder bed, important for posterior residual stresses analysis. The Finite Element Method proposed in this study is a transient thermal model, able to predict temperature distribution through different sections of the powder bed when performing a single track of the laser scanning. Furthermore, the impact of the laser power input is carried out utilizing SS 304L, a low cost Stainless Steel alloy that can be employed in the SLM process, in order to determine the influence on the temperature distribution along the different cross sections.

scholarly journals In Situ Mo(Si,Al)2-Based Composite through Selective Laser Melting of a MoSi2-30 wt.% AlSi10Mg Mixture

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3720 ◽  
Author(s):  
Tatevik Minasyan ◽  
Sofiya Aydinyan ◽  
Ehsan Toyserkani ◽  
Irina Hussainova
Keyword(s):  
High Temperature ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Laser Melting ◽  
Structural Applications ◽  
Laser Scanning Speed ◽  
Fusion Approach

The laser power bed fusion approach has been successfully employed to manufacture Mo(Si,Al)2-based composites through the selective laser melting of a MoSi2-30 wt.% AlSi10Mg mixture for high-temperature structural applications. Composites were manufactured by leveraging the in situ reaction of the components during printing at 150–300 W laser power, 500–1000 mm·s−1 laser scanning speed, and 100–134 J·mm−3 volumetric energy density. Microcomputed tomography scans indicated a negligible induced porosity throughout the specimens. The fully dense Mo(Si1-x,Alx)2-based composites, with hardness exceeding 545 HV1 and low roughness for both the top (horizontal) and side (vertical) surfaces, demonstrated that laser-based additive manufacturing can be exploited to create unique structures containing hexagonal Mo(Si0.67Al0.33)2.

Study on selective laser melting of commercially pure titanium powder

2018 ◽  
Vol 233 (7) ◽  
pp. 1794-1807 ◽  
Author(s):  
Kurian Antony ◽  
T Reghunathan Rakeshnath
Keyword(s):  
Energy Density ◽  
Laser Power ◽  
Titanium Powder ◽  
Laser Energy ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Laser Track ◽  
Laser Melting ◽  
Commercially Pure ◽  
Powder Particles

Laser additive manufacturing processes melt the powder particles using laser beam energy to form solid three-dimensional objects. This article mainly focuses on numerical analysis and experimentation of laser melting of commercially pure titanium powder. Numerical solutions to moving heat source problems were developed, and their influences on process parameters were validated. The energy density has a significant role in laser melting process. The numerical investigation demonstrates the significant effect of laser energy density on laser tracks. The laser power, distribution of powder particles, the absorptivity, density, and chemical constitution of powder materials are the main factors which influence the laser energy penetration. The absorptivity plays a vital role in consolidation phenomena of the powder layer which helps to get a denser part or layer. The experimental result clearly indicates that at lower laser speed the powder compaction is better. Temperature distribution, depth, and width of laser track were compared in this article. By investigating the observations from optical microscopic images and scanning electron microscopic images, the surface characteristics of laser-melted tracks were studied. The study on numerical and experimental results shows that the optimum condition for better laser track is laser power 45 W, laser speed 20 mm/s, and laser diameter 2.5 mm. This study provides important insights into laser parameters in the melting of commercially pure titanium powder.

Direct Selective Laser Sintering of WC-Co Cemented Carbide by Premixing of Additives

2012 ◽  
Author(s):  
Hideki Kyogoku ◽  
Takeshi Uemori ◽  
Akihiko Ikuta ◽  
Kenichi Yoshikawa ◽  
Hitoshi Ohmori
Keyword(s):  
Selective Laser Melting ◽  
Laser Power ◽  
Smooth Surface ◽  
Laser Scanning ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Cemented Carbides ◽  
Sintering Process ◽  
Laser Melting ◽  
Scan Speed

In this study, the fabrication conditions of WC cemented carbides by direct selective laser melting were investigated. The effects of additives, such as Co, Cu-20%Sn and Cu powders, and laser scanning conditions on laser sintering process were examined to fabricate a sound laser-scanned body of WC cemented carbides. The optimum laser power, scan speed and scan pitch were found out by experiments. It was found that the continuously smooth single-scan track can be obtained at a lower laser power and a higher scan speed by the addition of 30% Cu powder. The smooth surface of the laser-scanned body could be fabricated at a laser power of 9 W, a scan speed of 20 mm/s and a scan pitch of 0.05 mm.

Experimental Investigation into the Single-Track of Selective Laser Melting of IN625

2011 ◽  
Vol 233-235 ◽  
pp. 2844-2848 ◽  
Author(s):  
Li Wang ◽  
Qing Song Wei ◽  
Yu Sheng Shi ◽  
Jin Hui Liu ◽  
Wen Ting He
Keyword(s):  
Energy Density ◽  
Relative Density ◽  
Surface Quality ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Energy ◽  
Scanning Speed ◽  
Single Track ◽  
Laser Melting ◽  
Metallic Parts

Selective laser melting(SLM) is driven by the need to fabricate functional metallic parts and tools with near shape and density. The method of process to fabricate a metal part will save materials, time and energy compared to the traditional manufacturing methods. Unlike the selective laser sintering (SLS), the metal powder particles are molten by the laser beam during the process of selective laser melting. In this paper, IN625 powders were adopted to investigate the characters of single molten track. The factors that affect the surface quality and relative density are the process parameters such as the laser energy, scan speed and so on. They were studied to find out the correlation between the parameters and formation of single-track. It has been found that Optimal ratio between laser power and scanning speed (P/v) is 1-1.5 for IN625 SLM. P/v is the linear energy density. It also has been found that the width and height of single-track can be calculated when the linear energy density is given. In this study the laser power, scan spacing and the hatch spacing which affect the surface quality and the relative density of the metallic parts were optimized.

scholarly journals Formability, Microstructure and Properties of Inconel 718 Superalloy Fabricated by Selective Laser Melting Additive Manufacture Technology

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 991
Author(s):  
Xiaoping Liu ◽  
Kuaishe Wang ◽  
Ping Hu ◽  
Xiaomei He ◽  
Baicheng Yan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Selective Laser Melting ◽  
Inconel 718 ◽  
Laser Scanning ◽  
Laser Energy ◽  
High Surface ◽  
Additive Manufacture ◽  
Internal Cavity ◽  
Laser Melting ◽  
Manufacture Technology

Many urgently needed inconel superalloy parts with complex internal cavity geometry and high surface precision are difficult to prepare by traditional subtractive manufacturing methods because of its poor machinability. The additive manufacturing technology that has emerged in recent years became a research hotspot in the manufacture of refractory and difficult-to-process metals. In the present study, selective laser melting (SLM), a typical additive manufacture technology, was used to prepare Inconel 718 samples. The influences of input laser energy density ((E, J/mm3) on densification behavior, phases composition, microstructures, microhardness, and wear performance of the SLM as-built Inconel 718 samples were explored in detail. X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to examine the phase composition and microstructure evolutions. The results show that the formablity, microstructures and mechanical properties of the printed samples were all improved with the increase of E within the parameter setting range of this study. At a lower E, the poor surface morphology and balling effect occurred, the density, hardness, and wear resistance were all at a relatively lower level. When an E value of 190 J/mm was properly set, the surface open-pores and balling effect disappeared, the laser scanning tracks became smooth and continuous, the near-full dense (99.15%) and specimens with good metallurgical bonding and no critical defect were obtained, in which the average microhardness value reached 348 HV0.2 and wear rate was 5.67 × 10−4 mm3/N·m. The homogeneity of the superalloy Inconel 718 was also explored.

scholarly journals Modeling of Residual Stress Distribution for Components Manufactured by Selective Laser Melting

2019 ◽  
Vol 224 ◽  
pp. 05006
Author(s):  
Tong Ye ◽  
Xiaohui Jiang ◽  
Miaoxian Guo ◽  
Vladimir Kuptsov ◽  
Sergey Fedorov
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Residual Stress Distribution ◽  
Laser Melting ◽  
Laser Scanning Speed ◽  
Formed Part

In this paper, the selective laser melting (SLM) simulation analysis of components is carried out. The residual stress distribution of the formed part was predicted, and the influence of process parameters such as exposure time, laser power and laser scanning speed on the residual stress of the SLM formed part was analyzed. It was found that the residual stress concentration of the formed part was in the middle of the upper surface or the bottom surface. In addition, the laser power and the laser scanning speed have a great influence on the residual stress of the formed part. The results of this study lay a theoretical and experimental basis for the optimization of residual stress and quality control of SLM components.

scholarly journals Selective Laser Melting Strategy for Fabrication of Thin Struts Usable in Lattice Structures

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1763 ◽  
Author(s):  
Radek Vrána ◽  
Daniel Koutný ◽  
David Paloušek ◽  
Libor Pantělejev ◽  
Jan Jaroš ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Selective Laser Melting ◽  
Laser Scanning ◽  
Laser Energy ◽  
Lattice Structure ◽  
Processing Parameters ◽  
Laser Melting ◽  
Contour Lines ◽  
Lower Porosity ◽  
Linear Laser

This paper deals with the selective laser melting (SLM) processing strategy for strut-lattice structure production which uses only contour lines and allows the porosity and roughness level to be managed based on combination of the input and linear energy parameters. To evaluate the influence of a laser scanning strategy on material properties and surface roughness a set of experiments was performed. The single welds test was used to find the appropriate processing parameters to achieve continuous welds with known width. Strut samples were used to find a suitable value of weld overlapping and to clarify the influence of input and linear laser energy on the strut porosity and surface roughness. The samples of inclined hollow struts were used to compare the wall thickness with single welds width; the results showed about 25% wider welds in the case of a hollow strut. Using the proposed SLM strategy it is possible to reach a significantly lower porosity and surface roughness of the struts. The best results for struts with an inclination of 35.26° were achieved with 25% track overlapping, input energy in the range from 9 J to 10.5 J and linear energy Elin from 0.25 to 0.4 J/mm; in particular, the relative density of 99.83% and the surface roughness on the side of the strut of Ra 14.6 μm in an as-built state was achieved.

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