Effects of Laser Parameters on the Formation of Al2O3-TiC Coating by Laser-Assisted Combustion

2014 ◽  
Vol 597 ◽  
pp. 175-183
Author(s):  
Cai Xuan Lu ◽  
He Ping Li ◽  
Peng Chen ◽  
Li Hong Xue ◽  
You Wei Yan
Keyword(s):  
Laser Processing ◽  
Laser Power ◽  
Laser Scanning ◽  
Nuclear Reactor ◽  
Composite Ceramic ◽  
Scanning Speed ◽  
Combustion Method ◽  
Processing Parameters ◽  
Ceramic Coatings ◽  
Laser Scanning Speed

Nowadays, Al2O3-based ceramic coatings have attracted considerable attention for their potential applications as tritium permeation barrier (TPB) in the nuclear reactor. Herein, dense composite ceramic coatings (Al2O3-TiC) have been successfully fabricated by a facile laser-assisted combustion method. The precursor Al-TiO2-C powder mixture underwent combustion synthesis at high temperatures generated by an incident laser, and Al2O3-TiC coatings were thus obtained. Their crystal structures and morphologies were monitored by x-ray diffraction and field emission scanning electron microscopy. The laser processing parameters, including laser power and laser scanning speed, have been found to play an important role in the microstructure of the products. The optimal laser processing parameters for obtaining Al2O3-TiC coating were 4kW in laser power and 6mm/s in laser scanning speed. The results in this paper may be beneficial to the future study of other coatings fabricated by laser-assisted combustion.

Research on Microstructure and Wear Property of 45 Steel Quenched with Different Laser Power

2020 ◽  
Vol 861 ◽  
pp. 35-40
Author(s):  
Yu Liu ◽  
Tian Hao Xu ◽  
Ying Liu ◽  
Hai Cheng Zhang ◽  
Xing Xing Li ◽  
...  
Keyword(s):  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Wear Volume ◽  
Wear Property ◽  
Steel Matrix ◽  
Wear Properties ◽  
Laser Scanning Speed ◽  
Friction And Wear Properties ◽  
Minimum Wear

The surface of 45 steel is quenched by CO2 laser with scanning speed 1000 mm/min and different laser power 1000W, 1200W, 1400W, 1600W and 1800W. Experiments are carried out to analyze microstructure, friction and wear properties of quenched 45 steel. The results show that the quenching layer thickness increases gradually with the increase of laser power,and the maximum value of quenching layer hardness increases first and then decreases. When the laser power is 1600W, the maximum hardness value is 883HV0.5. But when the laser power is 1800W, the hardness of quenching layer becomes to decrease. The reason is the surface of 45 steel becomes to melt. The wear volume increases first and then decreases too. When laser power is 1600W, the minimum wear volume is 0.08mm3, which is 6.4% to the wear volume of 45 steel matrix without laser quenching. Therefore, better microstructure and properties of 45 steel can be obtained when laser scanning speed is 1000mm/min and laser power is 1600W.

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.

Laser-Energy-Density Dependent Formation of Al2O3-TiC Coating by Laser-Assisted Combustion

2014 ◽  
Vol 941-944 ◽  
pp. 2182-2189
Author(s):  
Cai Xuan Lu ◽  
He Ping Li ◽  
Peng Chen ◽  
You Wei Yan
Keyword(s):  
Energy Density ◽  
Powder Mixture ◽  
Laser Scanning ◽  
Laser Energy ◽  
Steel Substrate ◽  
Composite Ceramic ◽  
Scanning Speed ◽  
Ceramic Coatings ◽  
Medium Carbon Steel ◽  
Laser Energy Density

Al2O3-TiC composite ceramic coatings were obtained by laser-assisted combustion. Al-TiO2-C precursor powder mixture was coated on a medium-carbon steel substrate. When a laser scanned on the powder mixture, it went through combustion synthesis reaction triggered by the incident laser beam and formed the target products. The microstructure of the obtained coatings with different laser processing parameters was characterized using field emission scanning electron microscopy. The laser energy density, controlled by changing laser power and laser scanning speed, was found to play an important role on the microstructure of the products. The formation mechanism of different micro-morphologies with different laser energy densities was proposed according to thermodynamic calculation.

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.

Laser power and scanning speed influence on the microstructure, hardness, and slurry erosion performance of Colmonoy-5 claddings

2020 ◽  
Vol 234 (7) ◽  
pp. 947-961
Author(s):  
T Savanth ◽  
Jastej Singh ◽  
JS Gill
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Laser Processing ◽  
Laser Power ◽  
Erosive Wear ◽  
Scanning Speed ◽  
Processing Parameters ◽  
X Ray ◽  
High Scanning Speed ◽  
Scanning Electron

A 4kW Yb: YAG solid-state disc laser, with a four-way co-axial cladding head with powder feeding technique was employed to fabricate single-layer clads of Ni-based hardfacing alloy (Colmonoy-5) on medium carbon steel (ASME SA105) substrate by varying the laser processing parameters namely, beam power level (designated as low: 1200 W, medium: 1400 W, and high: 1600 W) and scanning speed (designated as low: 300 mm/min, medium: 400 mm/min, and high: 500mm/min). The laser clads were evaluated for their microstructural characteristics, microhardness, and slurry erosive wear performance with an aim to understand the effect of process parametric variations on their properties. Microstructural analyses of the clads were carried out using an optical microscope and a field-emission scanning electron microscope with attached energy-dispersive X-ray spectrometer supplemented by their Vickers microhardness testing and X-ray diffraction examination. The variation in laser processing parameters exerted a strong influence on the microstructural features of the clads in terms of γ-Ni dendrite size as well as morphology and distribution of various complex precipitates such as Cr-carbides and borides with relatively uniform distribution observed for the clads corresponding to low laser power and high scanning speed. The variation in laser power had relatively a greater influence on microhardness than the scanning speed variation. Micro-cutting, plastic deformation, crater formation besides ploughing away of the softer matrix were the typical fracture features associated with slurry eroded clads when examined under field-emission scanning electron microscope. Results of the slurry erosive wear tests showed that the clads pertaining to low laser power and high scanning speed exhibited superior wear resistance as compared to their counterparts.

Influence of Process Parameters on the Mechanical Response of Various Layers Processed Using Direct Metal Laser Sintering (DMLS)

2014 ◽  
Author(s):  
S. Ahmed ◽  
H. Doak ◽  
A. Mian ◽  
R. Srinivasan
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Laser Power ◽  
Laser Scanning ◽  
Mechanical Response ◽  
Scanning Speed ◽  
Direct Metal Laser Sintering ◽  
Influence Of Process Parameters ◽  
Microstructural Morphology ◽  
Laser Scanning Speed

During the DMLS process, sintering of the top layer creates melting and heat affected zone in previously sintered layers. In this paper, we will examine the effects of any given process parameter, such as laser power and laser scanning speed, on the mechanical properties and microstructural morphology within the processed layers.

scholarly journals Mesoscopic simulation of overlapping behavior in laser powder bed additive manufacturing

2021 ◽  
Author(s):  
Pan Lu ◽  
Liu Tong ◽  
Wang Wen-hao ◽  
Gao Yu ◽  
Zhang Cheng-lin ◽  
...  
Keyword(s):  
Energy Density ◽  
Molten Pool ◽  
Laser Power ◽  
Laser Scanning ◽  
Flow Behavior ◽  
Pure Copper ◽  
Scanning Speed ◽  
Powder Bed ◽  
Volume Energy ◽  
Laser Scanning Speed

Abstract The prediction of the flow behavior of Metal micro-molten pool is prerequisite for high-quality Laser Powder Bed Fusion (L-PBF). In this study, mesoscopic scale numerical simulation modelling for L-PBF process was used to help understand the melting process of pure copper micro-melt pool.In this study, the orthogonal test was designed to study the influence of laser power, laser scanning velocity, hatching space on the flow behavior of molten pool and the overlapping rate of adjacent molten tracks. The results shows that laser scanning speed has the greatest influence on both the size and overlapping rate of the molten pool, and the overall trend was that the size of molten pool continues to increase as the volume energy density increases, and the maximum molten pool size was 243.6um × 110um with volume energy density 370.037 J/mm3, overlapping rate of adjacent molten tracks was 48.84% with volume energy density 285.71 J/mm3. The optimized pure copper laser process parameters were obtained: laser power 300 KW, laser scanning speed 500 mm/s, hatching space 0.07mm, overlapping rate 48.84%.

Numerical simulation and experimental study on laser hardening process of the 42CrMo4 steel

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110446
Author(s):  
Hongwei Zhang ◽  
Meng Zhu ◽  
Siqi Ji ◽  
Jianjun Zhang ◽  
Hengming Fan
Keyword(s):  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Element Model ◽  
Laser Hardening ◽  
Hardening Process ◽  
42Crmo4 Steel ◽  
Pitch Bearing ◽  
Laser Scanning Speed ◽  
The Finite Element Model

The large diameter pitch bearing was made of steel 42CrMo4 and the laser hardening process was used to improve its surface properties. In this paper, a numerical approach which can predict the temperature field and the hardened depth is provided for the laser hardening process of the 42CrMo4 steel. According to the simplification of the raceway structure of pitch bearing, the finite element model was constructed using ABAQUS software. Based on the actual process parameters, the transient thermal analysis was accomplished and the distribution of temperature field is analyzed. The hardened depth is determined according to the proposed temperature range. Laser power, laser scanning speed, and spot diameter were considered as input parameters, the experimental studies were performed based on orthogonal design in order to study the effects of process parameters. The finite element model is validated. The surface roughness and microstructure studies on treated surfaces were conducted. Also the micro-hardness testing was performed. The results show that the laser hardening increases surface hardness by about 3.8 times than that of the base material. The three parameters of laser power, laser scanning speed, and spot diameter have a coupling effect on the surface treatment. The input laser power density is more important.

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.

Microstructure of Laser In Situ Synthesized TiBx+TiC Reinforced Composite Coatings

2014 ◽  
Vol 1061-1062 ◽  
pp. 526-529
Author(s):  
Jing Liang ◽  
Chao Wang ◽  
Sui Yuan Chen ◽  
Chang Sheng Liu ◽  
Cheng Yu Yang
Keyword(s):  
Laser Scanning ◽  
Composite Coatings ◽  
Scanning Speed ◽  
Processing Parameters ◽  
In Situ Synthesis ◽  
Optimal Processing ◽  
Reinforced Composite ◽  
The Matrix ◽  
Laser Scanning Speed

B4C/TiNi mixed powders with different composition (10B4C+90TiNi and 20B4C+80TiNi in wt. %) prepasted on Ti-6Al-4V substrates were scanned by a FL-Dlight02-3000W semiconductor laser to obtain TiBx+TiC reinforced graded composite coatings. The influences of the processing parameters on the microstructure of the coatings were studied. Optimal processing parameters were obtained with laser power (P) 1700W/1900W, laser scanning speed (V) 6.67mm/s and defocus length 310mm. The microstructures and phases of the coatings were analyzed with OM, SEM and XRD respectively. Graded composite coatings with in-situ synthesis of TiC, TiB and TiB2 reinforcements in the matrix of Ti2Ni and TiNi were obtained.

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