EFFECT OF LASER PROCESSING PARAMETERS ON THE COATING'S MICROSTRUCTURE AND QUALITY

2007 ◽  
Vol 14 (05) ◽  
pp. 885-890 ◽  
Author(s):  
Y. S. TIAN ◽  
D. Y. WANG ◽  
C. Z. CHEN
Keyword(s):  
Titanium Alloy ◽  
Output Power ◽  
Laser Processing ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Thickness Increase

The effect of laser processing parameters on the microstructure and quality of the coatings fabricated on titanium alloy has been investigated. Results show that the increase of the output power and the decrease of the scanning speed result in the thickness increase and the microstructure coarseness of the coatings. Overlapped fraction of the laser tracks significantly affects the coating's quality. With a lower overlapped fraction, pores and cracks easily occur in the overlapped area due to the inferior metallurgical quality.

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.

The Effect of Parameters of Laser Processing on the Morphology of Glaze Cladding

2012 ◽  
Vol 586 ◽  
pp. 265-268 ◽  
Author(s):  
Ji Wei Fan ◽  
Zhi Qiang Jiao ◽  
Xiao Peng Li ◽  
Hui Jun Zhao ◽  
Zhen Guo Zhang ◽  
...  
Keyword(s):  
Output Power ◽  
Processing Speed ◽  
Laser Processing ◽  
Ceramic Materials ◽  
Processing Parameters ◽  
Laser Technique ◽  
Experimental Conditions ◽  
Melted Zone

Laser processing ceramic materials is a new application of laser technique. This paper presents the study of laser processing parameters of glaze cladding. It found out that the parameters of laser processing affected the morphology of glaze cladding significantly. Within the experimental conditions, rise of output power or drop of processing speed can increase the depth of melted zone and the width of glaze cladding, vice versa.

scholarly journals Evaluation of the quality of layers applied by LDT laser metal deposition

2018 ◽  
Vol 19 (6) ◽  
pp. 591-596
Author(s):  
Andrzej Mazurkiewicz ◽  
Andrzej Poprzeczka
Keyword(s):  
Heat Affected Zone ◽  
Heat Dissipation ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Cross Sectional ◽  
Weld Overlay ◽  
The Cross

The article presents the results of a study of C45 carbon steel hardfacing using laser metal deposition with Stellit Co-21 powder. The microstructure of the cross-section of samples prepared with different scanning speed and the amount of used powder at constant laser power was observed. Analyzing the cross-sectional areas of the samples, it was found that, at specific production parameters, cracks occur in weld overlay, which should be associated with the amount of heat supplied and discharged, especially at the unheated basis.This may be confirmed by the presence of deposits of weakly branched dendrites in the microstructure, which should be related to the directional heat dissipation process and rapid directional crystallization. It is possible to regulate these phenomena by selecting appropriate processing parameters. The microstructure analysis of cross-sectional areas of samples after hardfacing using LDT technique indicates good metallurgical quality of the deposit with a small heat affected zone of about 660÷760m. The microhardness measurements on the sample cross-sections indicated a wide micohardness distribution ranging from 510HV1 in the weld overlay, about 410HV1 in the heat affected zone, to 270HV1 in the C45 steel base.

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”.

Fabrication and Biocompatibility of Gradient Bioceramic Coatings on Titanium Alloy Substrate by Laser Cladding

2008 ◽  
Vol 368-372 ◽  
pp. 1203-1205 ◽  
Author(s):  
Min Zheng ◽  
Ding Fan ◽  
Xiu Kun Li ◽  
Qi Bin Liu ◽  
Wen Fei Li ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Laser Cladding ◽  
Laser Processing ◽  
Rare Earth Oxide ◽  
Processing Parameters ◽  
Alloy Substrate ◽  
Gradient Composition ◽  
Titanium Alloy Substrate ◽  
Bioceramic Coatings

Based on a high power CO2 laser beam passing by pyramid polygon mirror, the bioceramic coatings of gradient composition were fabricated on titanium alloy substrate (Ti-6Al-4V). The relations among laser processing parameters, microstructure and biocompatibility of the gradient bioceramic coatings were investigated. The results indicated that the contents of rare earth oxide additions had an immediate effect on the formation of bioactive phases. The gradient bioceramic coatings showed favorable biocompatibility in vivo after they were implanted into canine femur for 45, 90, and 180 days, respectively. The bioceramic coatings of Ca/P=1.4 and 0.6wt.% Y2O3 totally combined with new bones merely implanted for 45 days. Furthermore, the MTT (Methyl Thiazolyl Tetrazolium) colorimetry results of cell proliferation demonstrated that the cell growth distinctly increased on the gradient bioceramic coatings by laser cladding compared with the un-treated titanium alloy substrate.

Contrast Test of KOH Solutions Jet-Assisted Laser Etching on Al2O3 Ceramics

2012 ◽  
Vol 472-475 ◽  
pp. 2476-2479 ◽  
Author(s):  
Gen Fu Yuan ◽  
Wei Zheng ◽  
Xue Hui Chen
Keyword(s):  
Surface Roughness ◽  
Cross Section ◽  
Laser Processing ◽  
Processing Parameters ◽  
Laser Etching ◽  
Composite Processing ◽  
Regular Shape ◽  
Material Sample ◽  
Melting Slag

An experimental device of KOH solutions jet-assisted laser etching is designed, Laser-chemical combined etching technology is combined with the Medium-jet erosion processing ,and the influence on the etching capacity and cross section quality of material sample of laser processing parameters,jet processing parameters are studied. The results show that the laser processing parameters and jet processing have a decisive impact on the quality of the workpiece, the composite processing technology can remove most of melting slag which are produced by the laser processing, the surface roughness are effectively reduced. The blind holes of the machined materials have the regular shape.

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.

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.

A New Method for Processing Ceramics with Cracked Glaze

2011 ◽  
Vol 418-420 ◽  
pp. 63-66
Author(s):  
Ji Wei Fan ◽  
Xiao Peng Li ◽  
Zhao Jun Zhang ◽  
Wang Xi Zhang ◽  
Zhi Qiang Jiao ◽  
...  
Keyword(s):  
Laser Processing ◽  
Ceramic Materials ◽  
Processing Parameters ◽  
Processing Method ◽  
New Method ◽  
Ceramic Surface ◽  
Laser Technique

Laser processing ceramic materials is a new application of laser technique. This paper presents the study of making cracked glaze surface by laser processing. Proposed the applicable the composition of glaze, the main processing parameters of laser processing, and discussed the factors which may affect the quality of cracked glazing surface. It indicates that laser processing could be a new and easy processing method to produce the cracked glazing on the ceramic surface.

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