scholarly journals PECULIARITIES OF SINGLE TRACK FORMATION FROM TI6AL4V ALLOY AT DIFFERENT LASER POWER DENSITIES BY SELECTIVE LASER MELTING

2015 ◽  
Vol 26 (3) ◽  
Author(s):  
I. Yadroitsava ◽  
J. Els ◽  
G. Booysen ◽  
Igor Yadroitsev
Keyword(s):  
Selective Laser Melting ◽  
Laser Power ◽  
Ti6al4v Alloy ◽  
Single Track ◽  
Laser Melting ◽  
Track Formation ◽  
Power Densities

Single Track Formation during Selective Laser Melting of Ti-6Al-4V Alloy

2019 ◽  
Vol 946 ◽  
pp. 978-983 ◽  
Author(s):  
R.M. Baitimerov
Keyword(s):  
Selective Laser Melting ◽  
Process Parameters ◽  
Complex Shape ◽  
Powder Layer ◽  
Single Track ◽  
Laser Melting ◽  
Additive Manufacturing Technology ◽  
Geometrical Characteristics ◽  
Track Formation ◽  
Point Distance

Selective laser melting (SLM) is an additive manufacturing technology that allows to produce functional parts with extremely complex shape from metal powder feedstock. 240 single tracks with the length of 10 mm were fabricated using different SLM process parameters: laser power output, powder layer thickness, point distance and exposure time. Obtained single tracks were measured using optical microscopy. An influence of SLM process parameters on geometrical characteristics of obtained single tracks was investigated.

scholarly journals Effects of the powder morphology, size distribution, and characteristics on the single track formation in selective laser melting of H13 steel

2021 ◽  
Vol 15 (3) ◽  
pp. JAMDSM0035-JAMDSM0035
Author(s):  
Mitsugu YAMAGUCHI ◽  
Tatsuaki FURUMOTO ◽  
Yuuya TANABE ◽  
Shinnosuke YAMADA ◽  
Mototsugu OSAKI ◽  
...  
Keyword(s):  
Size Distribution ◽  
Selective Laser Melting ◽  
Single Track ◽  
Laser Melting ◽  
H13 Steel ◽  
Powder Morphology ◽  
Track Formation

A Study of Keyhole Porosity in Selective Laser Melting: Single-Track Scanning With Micro-CT Analysis

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Subin Shrestha ◽  
Thomas Starr ◽  
Kevin Chou
Keyword(s):  
Selective Laser Melting ◽  
Laser Power ◽  
Scanning Speed ◽  
Single Track ◽  
Micro Computed Tomography ◽  
Laser Melting ◽  
Pore Characteristics ◽  
Line Energy ◽  
The Individual ◽  
Pore Number

Porosity is an inherent attribute in selective laser melting (SLM) and profoundly degrades the build part quality and its performance. This study attempts to understand and characterize the keyhole pores formed during single-track scanning in SLM. First, 24 single tracks were generated using different line energy density (LED) levels, ranging from 0.1 J/mm to 0.98 J/mm, by varying the laser power and the scanning speed. The samples were then scanned by micro-computed tomography to measure keyhole pores and analyze the pore characteristics. The results show a general trend that the severity of the keyhole porosity increases with the increase of the LED with exceptions of certain patterns, implying important individual contributions from the parameters. Next, by keeping the LED constant in another set of experiments, different combinations of the power and the speed were tested to investigate the individual effect. Based on the results obtained, the laser power appears to have a greater effect than the scanning speed on both the pore number and the pore volume as well as the pore depth. For the same LED, the pore number and volume increase with increasing laser power until a certain critical level, beyond which, both the pore number and volume will decrease, if the power is further increased. For the LED of 0.32 J/mm, 0.4 J/mm, and 0.48 J/mm, the critical laser power that reverses the trend is about 132 W, 140 W, and 144 W, respectively.

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 Selective Laser Melting of Pre-Alloyed NiTi Powder: Single-Track Study and FE Modeling with Heat Source Calibration

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7486
Author(s):  
Stanislav V. Chernyshikhin ◽  
Denis G. Firsov ◽  
Igor V. Shishkovsky
Keyword(s):  
Heat Source ◽  
Thermal Behavior ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Laser Power ◽  
Scanning Speed ◽  
Fe Modeling ◽  
Single Track ◽  
Laser Melting ◽  
Melt Pool

Unique functional properties such as the low stiffness, superelasticity, and biocompatibility of nickel–titanium shape-memory alloys provide many applications for such materials. Selective laser melting of NiTi enables low-cost customization of devices and the manufacturing of highly complex geometries without subsequent machining. However, the technology requires optimization of process parameters in order to guarantee high mass density and to avoid deterioration of functional properties. In this work, the melt pool geometry, surface morphology, formation mode, and thermal behavior were studied. Multiple combinations of laser power and scanning speed were used for single-track preparation from pre-alloyed NiTi powder on a nitinol substrate. The experimental results show the influence of laser power and scanning speed on the depth, width, and depth-to-width aspect ratio. Additionally, a transient 3D FE model was employed to predict thermal behavior in the melt pool for different regimes. In this paper, the coefficients for a volumetric double-ellipsoid heat source were calibrated with bound optimization by a quadratic approximation algorithm, the design of experiments technique, and experimentally obtained data. The results of the simulation reveal the necessary conditions of transition from conduction to keyhole mode welding. Finally, by combining experimental and FE modeling results, the optimal SLM process parameters were evaluated as P = 77 W, V = 400 mm/s, h = 70 μm, and t = 50 μm, without printing of 3D samples.

Melt Pool and Single Track Formation in Selective Laser Sintering/Selective Laser Melting

2014 ◽  
Vol 933 ◽  
pp. 196-201 ◽  
Author(s):  
Mohd Rizal Alkahari ◽  
Tatsuaki Furumoto ◽  
Takashi Ueda ◽  
Akira Hosokawa
Keyword(s):  
Laser Beam ◽  
Layer Thickness ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Single Track ◽  
Laser Melting ◽  
Consolidation Process ◽  
Melt Pool ◽  
Track Formation ◽  
Scan Speed

Selective Laser Sintering/Selective Laser Melting (SLS/SLM) is one of Additive Manufacturing (AM) processes that utilize layer by layer powder deposition technique and successive laser beam irradiation based on Computer Aided Design (CAD) data. During laser irradiation on metal powders, melt pool was formed, which then solidified to consolidated structure. Therefore, melt pool is an important behavior that affects the final quality of track formation. The study investigates the melt pool behavior through visualization of the consolidation process during the single track formation on the first layer. In order to understand the transformation process of metal powder to consolidated structure and mechanism involved, high speed camera was used to monitor the process. Yb:fiber laser beam was irradiated on metal powder at maximum power of 150W. The laser processing parameters such as laser power, scan speed and layer thickness were varied in order to investigate their influence on the consolidation process. The result shows the size of melt pool increased with laser power and decreasing with increment in scan speed. Furthermore, with the increase of layer thickness, melt pool formation was unstable with chaotic movement. Significant amount of molten powder splattering was recorded from the melt pool. At high layer thickness also, the molten powder formed spherical shaped and the solidified molten powder failed to wet with the substrate.

Single track formation in selective laser melting of metal powders

2010 ◽  
Vol 210 (12) ◽  
pp. 1624-1631 ◽  
Author(s):  
I. Yadroitsev ◽  
A. Gusarov ◽  
I. Yadroitsava ◽  
I. Smurov
Keyword(s):  
Selective Laser Melting ◽  
Metal Powders ◽  
Single Track ◽  
Laser Melting ◽  
Track Formation

scholarly journals Laser beam profiling: experimental study of its influence on single-track formation by selective laser melting

2015 ◽  
Vol 16 (7) ◽  
pp. 709 ◽  
Author(s):  
Ivan V. Zhirnov ◽  
Pavel A. Podrabinnik ◽  
Anna A. Okunkova ◽  
Andrey V. Gusarov
Keyword(s):  
Experimental Study ◽  
Laser Beam ◽  
Selective Laser Melting ◽  
Single Track ◽  
Laser Melting ◽  
Track Formation ◽  
Laser Beam Profiling

scholarly journals Influence of the Main Parameters of Selective Laser Melting on Stability of Single Track Formation when ‘Growing’ Parts from Copper Alloys

2019 ◽  
pp. 20-29 ◽  
Author(s):  
A.G. Grigoriyants ◽  
D.S. Kolchanov ◽  
A.A. Drenin ◽  
A.O. Denezhkin
Keyword(s):  
Selective Laser Melting ◽  
Copper Alloys ◽  
Melting Process ◽  
Scanning Speed ◽  
Single Track ◽  
Optimal Parameters ◽  
Laser Melting ◽  
Track Formation ◽  
The Stability ◽  
Lower Limits

Selective laser melting technology has the ability to directly produce finished parts, and is economically efficient for single or small batch production. Copper and its alloys are of great interest due to their high thermal and electrical conductivity. The influence of build process parameters, such as scanning speed and layer thickness on the stability of single track formation using a heat-resistant copper alloy PR-BrKh was investigated in this paper. The mechanism of single track formation was studied. As a result, patterns of formation of a stable single track were established, the upper and lower limits of the build parameters were determined. The results of the study provide a deeper understanding of the copper alloys selective laser melting process and may serve as a basis for determining the optimal parameters’ range for ‘growing’ solid structures.

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