scholarly journals Research on mechanism and process of paint removal with pulsed fiber laser

2018 ◽  
Vol 189 ◽  
pp. 01008
Author(s):  
Xiaodi Zeng ◽  
Wenbin Qin ◽  
Jing Li ◽  
Zhiyong Wang
Keyword(s):  
Energy Density ◽  
Fiber Laser ◽  
Laser Energy ◽  
Steel Substrate ◽  
Paint Layer ◽  
Laser Cleaning ◽  
Laser Energy Density ◽  
Cleaning Efficiency ◽  
Pulsed Fiber Laser ◽  
Paint Removal

Compared with the traditional cleaning technology, laser cleaning, as a new type of industrial technology, has the advantages of high cleaning rate, green pollution-free and low cost. So laser cleaning is widely used in the fields of paint removal. This paper analyzes that the mechanism of paint removal and heat transfer process in the paint layer and substrate, also determines the process parameters of affect the laser paint removal. The removal of paint from steel substrate with fiber laser of frequency adjustable 20 to 500kHz at 1064nm is reported, researching impact that laser energy density,scanning speed and line width on the paint removal effect. The results show that, the 100μm paint layer can be removed completely while keeping the substrate undamaged with the laser energy density of 10.19J/cm2 and speed of 4200mm/s and width of 0.02mm. In order to get better results, the cleaning efficiency can be improved by increasing the power, speed and spot size under the right energy density.

Removal characteristics of shop-primer paint by laser energy density in Q-switching fiber laser cleaning

2020 ◽  
Vol 34 (07n09) ◽  
pp. 2040042
Author(s):  
Ji-Eon Kim ◽  
Myoung-Soo Han ◽  
Jong-Do Kim
Keyword(s):  
Energy Density ◽  
Fiber Laser ◽  
Oxide Layer ◽  
Base Metal ◽  
Steel Surface ◽  
Laser Energy ◽  
Laser Cleaning ◽  
Low Energy ◽  
Laser Energy Density ◽  
Q Switching

In this study, we performed laser cleaning using a Q-switching fiber laser to remove the shop-primer paint and the oxide layer. An analysis of the surface cleaned by laser was carried out at various energy densities. The results showed that the oxide layer on the steel surface was not removed at a relatively low energy density, whereas the base metal was damaged under excessive energy density. We confirmed that it was essential to select an appropriate energy density for efficiently removing only the paint and the oxide layer without damaging the base metal in laser cleaning.

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 Properties of Jet-Plated Ni Coating on Ti Alloy (Ti6Al4V) with Laser Cleaning Pretreatment

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 248
Author(s):  
Xiao Wang ◽  
Mingyang Xu ◽  
Zhanwen Wang ◽  
Lida Shen ◽  
Mingbo Qiu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Energy Density ◽  
Oxide Layer ◽  
High Efficiency ◽  
Laser Energy ◽  
Laser Cleaning ◽  
Laser Energy Density ◽  
Wear Volume ◽  
Jet Electrodeposition

The surface mechanical properties of the Selective Laser Melting (SLM) formed Ti6Al4V samples were improved by adopting a novel laser cleaning pretreatment process combined with a jet electrodeposition process. This paper aimed to investigate the effects of different laser powers on the morphologies and adhesions of the nickel coatings. The advantages of the laser cleaning process are no grinding, no contact, high efficiency and environmental protection. The morphologies, adhesion, wear resistance, and hardness of the coatings were characterized. The results indicate that when the laser energy density reached 20% (4 J/cm2), the contaminations on the substrate and the oxide layer were removed and the crystalline grain of the coating was 15.3 nm. The shallow pits generated by laser burning increased the adhesion of the coatings. In addition, when the laser energy density increased to 6 J/cm2, a yellow oxide layer was produced on the surface of the cleaned titanium alloy. Moreover, the wear resistance of the titanium alloy after the nickel plating was improved. The wear volume was only 0.046 mm3, and the hardness increased to 1967.6 N/mm2.

scholarly journals Preliminary Laser Cleaning Studies of a Consolidated Prehistoric Basketry Coming from the Pile Building of Fiavè-Carera in the North-East of Italy

2006 ◽  
Vol 2006 ◽  
pp. 1-5 ◽  
Author(s):  
Romina Belli ◽  
Antonio Miotello ◽  
Paolo Mosaner ◽  
Laura Toniutti ◽  
Marta Bazzanella
Keyword(s):  
Energy Density ◽  
Material Removal ◽  
Laser Energy ◽  
Laser Cleaning ◽  
Original Surface ◽  
North East ◽  
The North ◽  
Cleaning Procedures ◽  
Krf Excimer Laser ◽  
Organic Deposits

In the archaeological field, some specific advantages are recognized to laser cleaning, like, for example, the absence of mechanical contacts with the sample. The cleaning procedures generally involve a multilayer structure (dust, dirty, organic deposits, and, in some cases, consolidant substances). In this work, prehistoric wood samples (found and consolidated in 1970s) have been laser irradiated (KrF excimer laser) in order to restore their original surface aspect. A certain amount of burned matter was also present. Samples came from a fragment of a prehistoric basketry found in the lake dwelling site of Fiavè-Carera, Trento, Italy (1500–1400 BC). It was observed that the laser cleaning effects are strictly dependent on the irradiation parameters (power density and number of pulses). Efficient material removal was possible by using appropriate energy density. Moreover, for lower laser energy density, special structures appeared on the surface of the consolidating substance that we attributed to heating-induced stresses on the consolidant surface.

Fundamentals of radiation heat transfer in AlSi10Mg powder bed during selective laser melting

2019 ◽  
Vol 25 (9) ◽  
pp. 1506-1515 ◽  
Author(s):  
Pei Wei ◽  
Zhengying Wei ◽  
Zhne Chen ◽  
Jun Du ◽  
Yuyang He ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Density ◽  
Negative Impact ◽  
Laser Energy ◽  
Melting Process ◽  
Laser Energy Density ◽  
Granular System ◽  
Laser Melting ◽  
Content Type ◽  
Powder Bed

Purpose This paper aims to study numerically the influence of the applied laser energy density and the porosity of the powder bed on the thermal behavior of the melt and the resultant instability of the liquid track. Design/methodology/approach A three-dimensional model was proposed to predict local powder melting process. The model accounts for heat transfer, melting, solidification and evaporation in granular system at particle scale. The proposed model has been proved to be a good approach for the simulation of the laser melting process. Findings The results shows that the applied laser energy density has a significantly influence on the shape of the molten pool and the local thermal properties. The relative low or high input laser energy density has the main negative impact on the stability of the scan track. Decreasing the porosity of the powder bed lowers the heat dissipation in the downward direction, resulting in a shallower melt pool, whereas pushing results in improvement in liquid track quality. Originality/value The randomly packed powder bed is calculated using discrete element method. The powder particle information including particle size distribution and packing density is taken into account in placement of individual particles. The effect of volumetric shrinkage and evaporation is considered in numerical model.

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