Influence of Layer Laser Sintering on Quality of Surface Layer Sintered Aluminum Powder PA-4

2015 ◽  
Vol 770 ◽  
pp. 205-208
Author(s):  
N.A. Saprykina ◽  
A.A. Saprykin ◽  
Ivan F. Borovikov
Keyword(s):  
Surface Layer ◽  
Aluminum Powder ◽  
Laser Processing ◽  
Laser Power ◽  
Experimental Studies ◽  
Scanning Speed ◽  
Powder Layer ◽  
Sintered Aluminum ◽  
Sintered Layer

The results of experimental studies of the influence of technological regimes of laser irradiation on the thickness of the surface layer of the sintered aluminum powder PA-4. The basic mode settings that affect the quality of the sintered surface layer - laser power, scanning speed and move the laser beam powder layer. The limits of variation of the thickness of the sintered layer from 0.74 to 1.55 mm by changing the technological conditions of laser processing.

Effect of Laser Processing Parameters on Microhole Quality of Aluminium Nitride Ceramics

2021 ◽  
Vol 871 ◽  
pp. 277-283
Author(s):  
Chun Yan Yang ◽  
Yun Hao ◽  
Bozhe Wang ◽  
Hai Yuan ◽  
Liu Hui Li
Keyword(s):  
Laser Processing ◽  
Laser Power ◽  
Picosecond Laser ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Recast Layer ◽  
Aluminium Nitride ◽  
Obvious Effect ◽  
Nitride Ceramics

A picosecond laser in spin-cutting mode was used to drill 500μm diameter microholes on 150μm thick aluminium nitride ceramic. The effects of laser processing parameters such as the laser power, scanning speed, and defocus amount on the microhole quality were studied. The results show that as the laser power increases, the inlet and outlet diameters of the holes increase, the taper decreases slightly, and the thickness of the recast layer decreases evidently. The scanning speed has no obvious effect on the diameter and taper of the hole; however, the hole can not be drilled through when the speed is too large. Positive defocus can effectively reduce the taper of the hole. Under 28.5W laser power, 400Hz frequency, 200mm/s scanning speed, and zero defocus amount conditions, high-quality microholes with a taper of 0.85° were obtained.

Effects of the Processing Parameters on the Forming Quality of Stainless Steel Parts by Selective Laser Melting

2011 ◽  
Vol 189-193 ◽  
pp. 3668-3671 ◽  
Author(s):  
Qing Song Wei ◽  
Xiao Zhao ◽  
Li Wang ◽  
Rui Di Li ◽  
Jie Liu ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Selective Laser Melting ◽  
Molten Pool ◽  
Laser Power ◽  
Single Layer ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Powder Layer ◽  
Laser Melting

Selective Laser Melting (SLM) can produce high-performance metal parts with complex structures. However, it’s difficult to control the processing parameters, because many factors involves. From the perspective of the molten pool, the study focuses on the effects of processing parameters, including scanning speed, laser power, scanning space, layer thickness, and scanning strategies, on the surface quality, the balling effect, the density of SLM parts, by conducting experiments of single track, single layer and block forming. The results show that the quality of the molten pool is affected by laser power and scanning speed. Scanning drove in the strategy of “jumping and turning”，a smooth surface and a less balling effect will be obtained. The thicker the powder layer is, the lower density will be obtained. The optimal parameters from series of experiments are: laser power of 98W; scanning speed of 90mm/s; scanning space of 0.07mm; layer thickness of 0.1mm; and scanning strategy of “jumping and turning”.

scholarly journals Selected Properties of the Surface Layer of C45 Steel Parts Subjected to Laser Cutting and Ball Burnishing

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3429 ◽  
Author(s):  
Agnieszka Skoczylas ◽  
Kazimierz Zaleski
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Laser Cutting ◽  
Experimental Studies ◽  
Hardened Layer ◽  
Ball Burnishing ◽  
Absolute Value ◽  
The Impact ◽  
Compressive Residual Stresses

In this article, we report the results of experimental studies on the impact of ball burnishing parameters on the roughness, microstructure and microhardness of the surface layer of laser-cut C45 steel parts. We also analysed the distribution of residual stresses generated in the surface layer of these parts. Laser-cut parts often require finishing to improve the quality of their surface. The tests performed in this study were aimed at assessing whether ball burnishing could be used as a finishing operation for parts of this type. Ball burnishing tests were performed on an FV-580a vertical machining centre using a mechanically controlled burnishing tool. The following parameters were varied during the ball burnishing tests: burnishing force Fn, path interval fw and the diameter of the burnishing ball dn. Ball burnishing of laser-cut C45 steel parts reduced the surface roughness parameters Sa and Sz by up to 60% in relation to the values obtained after laser cutting. Finish machining also led to the reorganization of the geometric structure of the surface, resulting in an increase in the absolute value of skewness Ssk. This was accompanied by an increment in microhardness (maximum microhardness increment was ΔHV = 95 HV0.05, and the thickness of the hardened layer was gh = 40 µm) and formation of compressive residual stresses in the surface layer.

scholarly journals Numerical Simulation of Moving Heat Flux during Selective Laser Melting of AlSi25 Alloy Powder

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 877
Author(s):  
Cong Ma ◽  
Xianshun Wei ◽  
Biao Yan ◽  
Pengfei Yan
Keyword(s):  
Numerical Simulation ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Molten Pool ◽  
Laser Power ◽  
Scanning Speed ◽  
Powder Layer ◽  
Maximum Temperature ◽  
Three Dimensional Model ◽  
Laser Melting

A single-layer three-dimensional model was created to simulate multi-channel scanning of AlSi25 powder in selective laser melting (SLM) by the finite element method. Thermal behaviors of laser power and scanning speed in the procedure of SLM AlSi25 powder were studied. With the increase of laser power, the maximum temperature, size and cooling rate of the molten pool increase, while the scanning speed decreases. For an expected SLM process, a perfect molten pool can be generated using process parameters of laser power of 180 W and a scanning speed of 200 mm/s. The pool is greater than the width of the scanning interval, the depth of the molten pool is close to scan powder layer thickness, the temperature of the molten pool is higher than the melting point temperature of the powder and the parameters of the width and depth are the highest. To confirm the accuracy of the simulation results of forecasting excellent process parameters, the SLM experiment of forming AlSi25 powder was carried out. The surface morphology of the printed sample is intact without holes and defects, and a satisfactory metallurgical bond between adjacent scanning channels and adjacent scanning layers was achieved. Therefore, the development of numerical simulation in this paper provides an effective method to obtain the best process parameters, which can be used as a choice to further improve SLM process parameters. In the future, metallographic technology can also be implemented to obtain the width-to-depth ratio of the SLM sample molten pool, enhancing the connection between experiment and theory.

Parameters Optimization of Laser Processing CVD Diamond Film Based on FEM Simulation

2010 ◽  
Vol 426-427 ◽  
pp. 26-29 ◽  
Author(s):  
X.J. Wu ◽  
Feng Xu ◽  
Dun Wen Zuo ◽  
Wen Zhuang Lu ◽  
M. Wang
Keyword(s):  
Temperature Distribution ◽  
Diamond Film ◽  
Laser Processing ◽  
Laser Power ◽  
Scanning Speed ◽  
Cvd Diamond ◽  
High Energy ◽  
Machining Parameters ◽  
Etching Depth ◽  
Cvd Diamond Film

Chemical vapor deposited (CVD) diamond film has a series of outstanding properties. However, it can not be easily machined by conventional technologies available currently for its high hardness and stability. Laser processing diamond film method can be an efficient way to process diamond film because of its high energy density. The mechanisms of laser processing diamond film are thermal oxidation, graphitization and evaporative ablation of graphite. Temperature distribution is of great importance to understand these complex phenomena taking place during the process because different temperatures lead to different physical and chemical changes of diamond. In this paper, the finite element method (FEM) software ANSYS is applied to calculate the temperature distribution. The relation between etching depth and laser machining parameters (laser power and scanning speed) is presented. The proper parameter ranges of laser power and scanning speed for a certain etching depth is also investigated with this method.

Influence of laser parameters and Ti content on the surface morphology of L-PBF fabricated Titania

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abid Ullah ◽  
HengAn Wu ◽  
Asif Ur Rehman ◽  
YinBo Zhu ◽  
Tingting Liu ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Laser Beam ◽  
Surface Quality ◽  
Selective Oxidation ◽  
Laser Power ◽  
Scanning Speed ◽  
Content Type ◽  
Powder Bed ◽  
Laser Parameters

Purpose The purpose of this paper is to eliminate Part defects and enrich additive manufacturing of ceramics. Laser powder bed fusion (L-PBF) experiments were carried to investigate the effects of laser parameters and selective oxidation of Titanium (mixed with TiO2) on the microstructure, surface quality and melting state of Titania. The causes of several L-PBF parts defects were thoroughly analyzed. Design/methodology/approach Laser power and scanning speed were varied within a specific range (50–125 W and 170–200 mm/s, respectively). Furthermore, varying loads of Ti (1%, 3%, 5% and 15%) were mixed with TiO2, which was selectively oxidized with laser beam in the presence of oxygen environment. Findings Part defects such as cracks, pores and uneven grains growth were widely reduced in TiO2 L-PBF specimens. Increasing the laser power and decreasing the scanning speed shown significant improvements in the surface morphology of TiO2 ceramics. The amount of Ti material was fully melted and simultaneously changed into TiO2 by the application of the laser beam. The selective oxidation of Ti material also improved the melting condition, microstructure and surface quality of the specimens. Originality/value TiO2 ceramic specimens were produced through L-PBF process. Increasing the laser power and decreasing the scanning speed is an effective way to sufficiently melt the powders and reduce parts defects. Selective oxidation of Ti by a high power laser beam approach was used to improve the manufacturability of TiO2 specimens.

Effect of processing parameters on forming defects during selective laser melting of AlSi10Mg powder

2020 ◽  
Vol 26 (5) ◽  
pp. 871-879 ◽  
Author(s):  
Haihua Wu ◽  
Junfeng Li ◽  
Zhengying Wei ◽  
Pei Wei
Keyword(s):  
Selective Laser Melting ◽  
Laser Power ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Argon Pressure ◽  
Powder Layer ◽  
Laser Melting ◽  
Content Type ◽  
Scan Speed ◽  
Forming Defects

Purpose To fabricate a selective laser melting (SLM)-processed AlSi10Mg part with almost full density and free of any apparent pores, this study aims to investigate the effect of ambient argon pressure and laser scanning speed on the particles splash during the AlSi10Mg powder bed laser melting. Design/methodology/approach Based on the discrete element method (DEM), a 3D model of random distribution of powder particles was established, and the 3D free surface of SLM forming process was dynamically tracked by the volume of fluid, where a Gaussian laser beam acts as the energy source melting the powder bed. Through the numerical simulation and process experimental research, the effect of the applied laser power and scanning speed on the operating laser melting temperature was studied. Findings The process stability has a fundamental role in the porosity formation, which is process-dependent. The effect of the processing conditions on the process stability and the resultant forming defects were clarified. Research limitations/implications The results shows that the pores were the main defects present in the SLM-processed AlSi10Mg sample, which decreases the densification level of the sample. Practical implications The optimal processing parameters (argon pressure of 1,000 Pa, laser power of 180 W, scan speed of 1,000 mm/s, powder layer thickness of 35 µm and hatch spacing of 50 µm ) applied during laser melting can improve the quality of selective laser melting of AlSi10Mg, Social implications It can provide a technological support for 3D printing. Originality/value Based on the analysis of the pore and balling formation mechanisms, the optimal processing parameters have been obtained, which were argon pressure of 1,000 Pa, laser power of 180 W, scan speed of 1,000 mm/s, powder layer thickness of 35 µm and hatch spacing of 50 µm. Then, a near-fully dense sample free of any apparent pores on the cross-sectional microstructure was produced by SLM, wherein the relative density of the as-built samples is larger than 97.5%.

scholarly journals Multi-objective numerical simulation of geometrical characteristics of laser cladding of cobalt-based alloy based on response surface methodology

2020 ◽  
pp. 002029402094495
Author(s):  
Lu-jun Cui ◽  
Meng Zhang ◽  
Shi-Rui Guo ◽  
Yan-Long Cao ◽  
Wen-Han Zeng ◽  
...  
Keyword(s):  
Prediction Model ◽  
Response Surface ◽  
Laser Cladding ◽  
Process Parameters ◽  
Laser Power ◽  
Influence Factors ◽  
Scanning Speed ◽  
Laser Cladding Remanufacturing ◽  
Main Influence

The objectives of this study are to optimize the key process parameters of laser cladding remanufacturing parts, improve the sealing quality of the hemispherical valve and prolong and improve its service life and reliability. A high-power fiber-coupled semiconductor laser was used to fabricate a single Co-based alloy cladding layer on the pump valve material ZG45 plate. The key process parameters of laser power, scanning speed and powder feeding rate in the process of laser remanufacturing are taken as optimization variables, and the coating width, coating height, coating depth, aspect ratio and dilution rate are taken as response indexes. Based on the response surface analysis method, the central compound experiment is designed using Design-Expert software. The variance analysis of the experimental results is performed, and the regression prediction model of the process parameters relative to the corresponding index is established. Through analysis of the established perturbation diagram and three-dimensional response surface, it is concluded that the main influence factors of melting width and penetration depth are laser power and positive effect, and the main influence factors of melting height are scanning speed and negative effect. The average error of each regression prediction model is lower than 10%. The above research work has important guiding significance for optimizing the process parameters and improving the cladding quality of cobalt-based alloy on ZG45.

Establishing the Optimal Process Parameters for the Laser Sintering of Ti64 for Layer Thicknesses of 15 μm and 30 μm and Validation of a Melt Pool Simulation Model

2014 ◽  
Vol 1019 ◽  
pp. 254-258 ◽  
Author(s):  
Johan Els ◽  
Michele Truscott ◽  
Kobus van der Walt ◽  
Gerrie Booysen
Keyword(s):  
Computer Aided Design ◽  
Laser Power ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Layer By Layer ◽  
Track Width ◽  
Melt Pool ◽  
High Laser Power ◽  
High Laser

Direct Metal Laser Sintering (DMLS) is a layer-by-layer Additive Manufacturing (AM) process that creates physical metal parts from three dimensional Computer Aided Design (CAD) data. For DMLS to be generally accepted by industry as a manufacturing technology, high mechanical integrity of final components needs to be demonstrated. Mechanical properties of manufactured components are directly affected by the quality of each individual laser sintered track of each consecutive layer. In this study, the optimal ratio of laser power and scanning speed on single tracks is determined for Titanium-6Al-4V powder on an EOSINT M270 DMLS machine for a layer thickness that varies between 15 μm and 30 μm. Two different laser powers, namely 150 W and 170 W were considered. Scanning speeds varied between 600 mm/s to 2000 mm/s with 200 mm/s intervals. The most stable tracks resulted from high laser power, slow scanning speed and thin powder distribution. The empirical data were compared to a melt pool width prediction program, which was found to underestimate track width at all scanning speeds and re-melting depth at low scanning speeds. Further, it was found that decreased powder thickness can be used with an increased scanning speed and high laser power. This strategy may be used to increase surface quality. The penetration data during fusion of the tracks onto the building platform further validates the quality of each sintered track.

scholarly journals Surface Laser Processing of Additive Manufactured 1.2709 Steel Parts: Preliminary Study

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
O. Černašėjus ◽  
J. Škamat ◽  
V. Markovič ◽  
N. Višniakov ◽  
S. Indrišiūnas
Keyword(s):  
Wear Resistance ◽  
Laser Processing ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Surface Conditions ◽  
Metal Parts ◽  
Processing Times ◽  
Surface Laser ◽  
Preliminary Study

Recently, metal selective laser sintering (SLS) techniques have attracted lively interest as a promising technology, which offers a number of unique applications in manufacturing of metal parts with complex internal structure and geometry. However, unsatisfactory surface properties of as-manufactured SLS parts cause high cost of finish processing and restrict wider application of SLS products. The paper presents results of the study, which was taken to evaluate capability of laser processing to improve surface quality of SLS parts manufactured from powder maraging steel 1.2709 (X3NiCoMoTi 18-9-5). The properties of processed surfaces were assessed, and the main dependencies of the roughness, hardness, wear resistance, and phase composition on the main parameters of laser processing—scanning speed, laser power, and number of processing times—were determined. The roughness of surfaces was diminished up to ∼41%, the hardness was increased up to ∼88%, and the wear resistance was improved up to almost 4 times, as compared with surface of as-manufactured SLS part. The preliminary study has demonstrated that laser processing has considerable potential for improvement of surface conditions of steel additive manufactured parts.

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