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The contribution deals with the laser marking as one of the progressive and environment friendly technologies with utilisation in many branches of industry. Engraving and other types of laser marking of different types of materials are very actual technologies these days. Laser marking decreases the waste creation in comparison with the other classical marking technologies, which use paintings or created chips. In this experimental investigation the laser marking surface texturing of material AL99,7 according to STN 42 4003:1993-08 (STN EN 573) has been conducted. The laser marking machine TruMark 6020 and software TruTops Mark were used. Laser surface texturing after laser marking has been realised under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of engraving or annealing surfaces has been performed using scanning electron microscopy (SEM) technique. The evaluation of roughness of engraved surfaces has been realized according to STN EN ISO 4287 by using Surftest SJ 301. The aim of the contribution was to show how different laser parameters affect the surface texture and colour change of metallic materials while creating minimal waste.
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Open Eng. 2017; 7:303–316
Research Article
Lydia Sobotova* and Miroslav Badida
Laser marking as environment technology
https://doi.org/10.1515/eng-2017-0030
Received Nov 03, 2016; accepted Aug 06, 2017
Abstract: The contribution deals with the laser marking
as one of the progressive and environment friendly tech-
nologies with utilisation in many branches of industry. En-
graving and other types of laser marking of dierent types
of materials are very actual technologies these days. Laser
marking decreases the waste creation in comparison with
the other classical marking technologies, which use paint-
ings or created chips. In this experimental investigation
the laser marking surface texturing of material AL99,7 ac-
cording to STN 42 4003:1993-08 (STN EN 573) has been
conducted. The laser marking machine TruMark 6020 and
software TruTops Mark were used. Laser surface texturing
after laser marking has been realised under dierent com-
binations of process parameters: pulse frequency, pulse
energy and laser beam scanning speed. The morpholog-
ical characterization of engraving or annealing surfaces
has been performed using scanning electron microscopy
(SEM) technique. The evaluation of roughness of engraved
surfaces has been realized according to STN EN ISO 4287
by using Surftest SJ 301. The aim of the contribution was
to show how dierent laser parameters aect the surface
texture and colour change of metallic materials while cre-
ating minimal waste.
Keywords: laser marking, technology, material, mi-
crostructure, roughness, environment
1Introduction
The laser technology is one of the progressive technolo-
gies, which enables towiden the utilization in various
parts of production and industry. According to the infor-
mation from the producers and users, the environmental
safety conditions and waste minimization are diminish-
*Corresponding Author: Lydia Sobotova: Technical University in
Kosice, Faculty of Mechanical Engineering Department of Process
and Environmental Engineering; Email: lydia.sobotova@tuke.sk
Miroslav Badida: Technical University in Kosice, Faculty of Me-
chanical Engineering Department of Process and Environmental
Engineering
ing in the world. They have become questions associated
with the requirements for quicker production. The mini-
mizations of the waste and permanent marking of prod-
ucts in the case of changes during the life-service or af-
ter damage of parts or during the identication of prod-
ucts are the important requirements of the producers and
customers. Laser beam machining of processed materials
has become a viable alternative to the conventional meth-
ods of machining of materials with changing properties
such as strength, stiness, toughness, resistance to cor-
rosion and biological compatibility [1]. The laser marking
is one of the possibilities to achieve these requirements.
The contribution deals with the testing of material sheet
AL99, 7 (STN 42 4003:1993-08) suitable for various ranges
of forming applications. Laser marking results showed the
possibility of the laser application to generate dierent
surface structures for tribological modication of metallic
materials and design too. Tested samples and structures
were obtained by varying the processing conditions be-
tween surface engraving and surface re-melting. The eval-
uation of the achieved results of realized experiments has
been realized by visual evaluation of obtained surfaces,
roughness measuring and metallographic results. The mi-
crostructure and images of morphology of laser engrav-
ing tested samples have been expressed by using metallo-
graphic microscope Olympus and also illustrated by SEM
microscope FEI QUANTA 400 with analyser EDAX. These
experiments were prepared in cooperation with TRUMPF
Slovakia, s.r.o.
2Laser marking
Laser micromachining and laser marking processes are
based on the interaction of electromagnetic radiation with
a material. The mechanism of material removal includes
dierent stages during this process: (a) melting, (b) vapor-
ization and (c) chemical degradation. When a high energy
density of laser beam is focused on the workpiece surface,
the thermal energy is absorbed, which heats and trans-
forms the work volume into molten, vaporized or chem-
ically changed material that can be easily removed by
ow of high pressure assist gas jet [2, 3]. There are many
methods of part or product marking, including labels,
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ink systems, embossing, mechanical engraving, chemical
and dry etching. During material marking with classical
methods, many technological steps must be done, which
are linked with energy consumption and waste occurring
(e.g. tins with paints, worn tools, chips and chemicals)
[4, 5]. Each marking method has its use, but laser mark-
ing is growing more and more popular and also becom-
ing a very important tool for the development of rapidly
growing micro - technology industry. The marking con-
trast can be achieved by the surface material removal
or the colour change. When infrared lasers have been
used, marking contrast relied on thermal eects. When UV
lasers, such as excimer lasers have been used, marking
contrast achieved through a photo-chemical transforma-
tion (i.e. colour change) [5, 6]. The utilisation of laser tech-
nology in metal processing is shown in Figure 1.
Reversible interaction between the laser beam and the
work-piece, product or tool forms the basis for each pro-
cess. Figure 2 shows the interaction of laser radiation with
the workpiece from various materials, where the incom-
ing laser energy, reection, absorption and transmission
of laser beam into processed materials are shown [5–9].
Figure 1: Percentage of laser used technologies [8]
Figure 2: The absorption of material vs. wavelength [7]
It is also important to understand, how the marked
material absorbs laser light at the wavelength of the cho-
sen laser. The absorptivity is the most important mate-
rial parameter of the workpiece in laser-material interac-
tion. For each conguration the absorptivity is given by the
combination of laser parameters (i.e. wavelength, angle of
incidence and polarization of the laser radiation) and the
material radiative properties, state, geometry of the sur-
face and temperature. A higher value of the resulting ab-
sorptivity means that more laser radiation is used for the
processing [6]. Ferrous and non-ferrous materials have ex-
cellent absorption at 1064 nm, while precious metals do so
at 355 and 532 nm [7]. The surface nishing and the coat-
ing of the workpiece also aect the absorptivity. Bare metal
surface will be dicult to be marked by CO2lasers, but it
can be easily marked by Nd:YAG or excimer lasers.
Laser marking of materials [5, 6] uses various marking
methods as shown in Table 1.
In engraving, the laser beam removes part of the par-
ent material. The mark is visible as a depression [5].
In ablation, the laser removes a coating layer. The un-
derlying base material is visible in the mark [5].
In annealing and colour change processes, the laser
heats the workpiece, altering the colour. The surface re-
mains smooth [5].
In foaming, reactions in the plastic material produce
gas bubbles, which form a raised, or textured, mark [5].
When selecting a laser marking system for a particular
application, there are many factors to consider [9]:
power density,
thermal: thermal conductivity, heat capacity, melt-
ing point and heat of vaporisation,
reectivity: material, wavelength and temperature.
In the marking process, the used energy density is of-
ten high enough that the desired vaporization completes
in microseconds. A series of vaporized craters in a surface
usually alters its appearance. The marking contrast de-
pends on the chemistry of the material, the surface nish-
ing and the colour. A good mark edge resolution is achiev-
able. The mark depth and the width are controllable. Mate-
rials such as plastic, glass, ceramic, rubber and metals will
be slightly engraved with a distinct change of the surface
structure [9].
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Table 1: Laser marking technologies [5]
Table 2: Technical parameters of TruMark 6020
solid-state crystal Nd: YAG
mode of work pulse
wavelength 1064 nm
pulse repetition frequency 1-120 kHz
min. focal diameter 42/45 µm
max. marking eld size 120 x 120 mm
max. power 20 KW
calibre accuracy - scanner ±50 µm
max. power consumption 230 V; 115 V
frequency consumption 50,Hz; 60 Hz
3Experimental research, method,
set up and discussion
The experimental method and testing of the marked mate-
rial samples were prepared in the laboratories of Technical
University of Kosice, Faculty of Mechanical Engineering,
the Department of Process and Environmental Engineer-
ing and in Trumpf Slovakia, s.r.o.
The laser machine parameters are shown in Table 2.
We used the laser marking machine TruMark 6020 and
software TruTops Mark for the testing of the chosen mate-
rial at various technological parameters.
During the experiment Trumpf navigator system was
used, which served for the right laser setting for the tested
materials. Figure 3 shows the navigator tested engraved
Figure 3: The example of the engraved samples: 1 - pulse frequency,
2 - speed engraving, 3 - description of the eld, 4 - number of repe-
titions
matrix elds. In each testing eld various testing param-
eters were chosen.
During the laser marking, the pattern of engraving de-
termines:
the overlap of runs and lines (visible under the mi-
croscope),
the angle of the incident beam: 90degrees,
the number of repetitions - determined number of
times the laser beam passes over a given quadrant,
the sample lines pitch 0.03 mm (Figure 4),
the rotation angle of 17 degrees of the next repetition
(Figure 5).
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Figure 4: Line pitch at laser marking
Figure 5: Rotating angle of laser beam
In the research experiment, we used material AL 99,7
according to STN 42 4003:1993-08 (STN EN 573), the me-
chanical properties and the chemical properties of which
are shown in Table 3 and Table 4 respectively.
The shape and the dimension of testing samples are
shown in Figure 6.
In the experiment the laser beam ran through the
tested material according the navigator and created the
testing elds (Figure 7). The rst evaluation of the surface
quality and the colour change of the tested material was
done visually and by using USB microscope. The colour
and surface qualities of the tested elds were varying and
dependent on the technological parameters. We chose the
most contrasting elds with the dierent colours from the
tested samples (the darkest one and the lightest one) for
the next microscope evaluation.
In practice, when the parts must be marked for control
or for evidence, it is necessary to make and create contrast
labelling of products.
We used the USB microscope for quick and better
macro view evaluations. The colour of the marked surfaces
changed from silver through grey to black, depending on
the laser parameter changes (Figure 8 and Figure 9).
From the point of view of surface microgeometry, the
surfaces are classied as oriented and non-oriented [9].
The surfaces of the tested elds, where the laser beam
processed the material, can be divided into:
re-melted oriented surfaces with created lines (the
laser beam cross the surface only once) after laser
marking with lower speed of laser beam,
re-melted non-oriented surfaces with crossing of
laser beam through the surface more than once.
Figure 8 shows three types of testing elds with var-
ious parameters, according to the navigator. The surface
of the eld A0 is non-oriented, but the elds A3 and A7
started to show very ne oriented lines.
Figure 9 (surfaces of the elds A0, A3, A7) shows ori-
ented elds. The lines with laser beam tracks are visible
without any problem.
The microscope OLYMPUS was used next for more de-
tailed evaluation of the surface. The microstructures of
marked material from the elds (A0, A3, A7) are shown in
Figure 10, Figure 11 and Figure 12. During the processing
of the elds A0, A3, A7, the stabile marking parameters:
speed 20 mm/s and frequencies 10, 40 and 80 kHz were
used.
In the eld A3 (Figure 11), the line spacing at the fre-
quency 40 kHz is seen. According to visual evaluation, sig-
nicant line spacing is seen in the eld A7 at the frequency
of 80 kHz, which is the maximal frequency value for the Al
material.
The surface of eld A0 is non-oriented and melted
with evaporated locations. The elds of A3 and A7 have
oriented surfaces.
Figure 13, Figure 14 and Figure 15 show the microstruc-
tures from the testing elds F0, F3 and F7. During the pro-
cessing of elds F0, F3 and F7, the stabile speed of marking
was 220 mm/s and the frequencies were 10, 40 and 80 kHz.
In eld F0, - line spacing at pulse frequency 10 kHz is seen,
which was not seen in eld A0. According to visual evalu-
ation, in eld F3 signicant line spacing is seen after laser
marking and in eld F7 the fusion of Al material started,
material - melted and the line spacing was not so signi-
cant at the frequency of 80 kHz. In Figure 14, the best lines
in the material surface in the tested elds were reached.
In Figure 16 the microstructure after rotation of laser
beam is seen and the changed angle in the navigator is
as shown in Figure 5. The laser beam crossed the material
four times. The surface layer became re-melted and non-
oriented.
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Table 3: Mechanical properties of tested material – Al 99,7
Description of material Cross section [mm2] Rm
[MPa]
Elongation
A10 [%]
Hardness Brinell HB
42 4003 0,2 to 10 max. 90 25 17-23
Table 4: Chemical properties of tested material – Al 99,7 [%]
Description of material Al Admixtures
42 4003 min 99,7 0,015 Cu / 0,16 Fe / 0,16 Si / 0,1 others
A B
Figure 6: Samples: A-The sample for engraving with geometrical parameters, B - example of the real sample from aluminium
Figure 7: The tested sample according to the navigator with
changed laser beam parameters
For more detailed evaluation of the tested results, we
investigated the tested laser marked samples also by the
SEM microscope FEI QUANTA 400 with analyser EDAX.
The SEM analyses of chosen tested elds are shown in Fig-
ure 17 to Figure 22.
Figure 17 shows the SEM microstructure of the tested
eld A0. The surface of the tested sample after laser mark-
ing is non-oriented. In the tested eld we can see the evap-
orated locations and the surface tops, which are not in one
layer. The surface is pleated.
The chemical composition of material Al 99,7 from
eld A0 is shown in Table 5.
The cross section of the tested sample, eld A0, left
side, is shown in Figure 18. The border on the left side be-
tween the original, non- processed surface and the laser
marked surface is observable. Between each laser beam
marked lines the depths of craters can be seen with depth
values around 136,1 µm. The depth and the shape of the
lines are nearly the same. The projections are compact and
in the interspaces residual oxides are visible.
The cross section of the tested sample, eld A0, right
side, is shown in Figure 19. We can see various depths of
the marked sample. The measured depth at the border is
176,4 µm. The original surface of the tested eld A0 is with-
out defects and on the right side. In the interspaces resid-
ual oxides are visible. In Figure 19 it is seen that, during the
starting of laser marking, the occurrence of deeper lines
are created, which is dependent on the starting and burn
of the laser beam.
Figure 20 show the microstructure of tested eld F7.
The surface of the tested sample after laser marking is ori-
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Figure 8: Visually chosen experimental samples, elds A0, A3, A7
Figure 9: Visually chosen experimental samples, elds F0, F3, F7
Figure 10: Microstructure of Al 99,7 material, eld A0, non-oriented surface
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Figure 11: Microstructure of Al 99,7 material, eld A3, oriented surface
Figure 12: Microstructure of Al 99,7 material, eld A7, oriented surface
Figure 13: Microstructure of AL 99,7 material, eld F0
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Figure 14: Microstructure of AL 99,7 material, eld F3, oriented surface
Figure 15: Microstructure of AL 99,7 material, eld F7
Figure 16: The example of microstructure after rotation of laser beam
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Table 5: Field A0 - SEM results
Field A0 - SEM results
Table 6: Field F7 - SEM results
Field F7 - SEM results
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Figure 17: SEM microstructure, eld A0
Figure 18: The cross section of the tested eld A0 on the left side
Figure 19: The cross section of the tested eld A0 on the right side
Figure 20: SEM microstructure, Field F7
Figure 21: The cross section of the tested eld F7 on the left side
Figure 22: The cross section of the tested eld F7 on the right side
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Table 7: Proles of material Al 99,7, testing elds A
ented. We can see the lines after crossing of the laser beam.
The lines are repeated at the same distance which is im-
portant for marking, to obtain homogeneous and similar
surfaces, with the same colour of the marked eld.
The chemical composition of material Al 99,7 from
eld F7 is shown in Table 6.
The cross section of the tested sample, eld F7 (left
side) is shown in Figure 21. The border between original
surface and laser marked surface is clear. Between each
laser beam marked lines, various depths can be seen with
values around 50,3 µm. The projections are compact and
the interspaces are shallow and the residual oxides are vis-
ible in the interspaces, too.
With the changing of the laser parameters of the tested
eld F7, the distance between the lines of the tested sample
are nearly the same except at the beginning of the marking.
The shape of the lines is changed. They are not so deep,
but are wider as in the elds A7. The small deviations of
the shape occurred at the starting of the marking process.
The cross section of the tested sample, eld F7, right
side, is shown in the Figure 22. We can see the various
depths of the marked sample. The measured depth at the
border is 42,4 µm. The original surface of the tested eld F7
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Table 8: Proles of material Al 99,7, testing elds F
is without defects and on the right side. In the interspaces
residual oxides are visible.
The surface microgeometry is dependent on the
marked material properties and the technological param-
eters of laser.
Regarding a specic character of microgeometry of
marked surfaces the most suitable and elaborated is the
evaluation of surface structure by prole-method using a
contact prole-meter. For the evaluation of roughness of
laser marked surfaces the quantities normalized in STN EN
ISO 4287 were used. As the chosen measured parameters,
Ra (arithmetical mean deviation of the prole on the sam-
pling length, as the most frequently used quantity) and Rz
(maximum height of prole on the sampling length, as the
second roughness parameter) were used.
The roughness evaluation was carried out in accor-
dance with STN EN ISO 4287 using Surftest SJ-201. Settings
for roughness measurement were- measured prole: Ra,
lter: GAUSS, sampling length l (λc): 0,25 mm, number
of sampling lengths: N = 5 and number of measured pro-
les:13. The changes of the surface character can be seen
from the proles measured on material Al 99, 7 in Table 7
and Table 8.
The values of micro-hardness of Al 99,7 material, mea-
sured by micro-hardness machine HMV-2, were changed in
relation to the testing eld. The greatest value of micro-
hardness 106, 85 was measured in the sample eld A0. Af-
ter changing the laser parameters in the elds A0, A3 and
A7, the micro-hardness values decreased from 106, 85 to
50,3.
4Conclusion
From laser marking methods, the laser micro machining
and laser marking are the best and the mostly applied tech-
niques nowadays to create permanent marks on a wide
range of materials and that is why we used them in our
research. We realized experimental works on a set of test
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samples. The test results with dierent surface morphol-
ogy can serve to widen the information in the parameter
databases of laser marking of materials.
From the experimental results of material marking
tests with various laser parameters, we chose dierent
laser parameters and made the conclusions:
During the visual evaluation of colour scale of en-
graved surface of Al samples, we found that, with
the increase of the pulse frequency and speed, the
colour of engraving square passes to a lighter colour
shade. The colour scale was changed from silver to
black colours depending on the technological pa-
rameters. The USB microscope can be used for quick
evaluation of surface and colour.
When we observed the microstructure of material
AL 99,7 by the microscope OLYMPUS, we found that
with the increase of pulse frequency and speed, ori-
ented structure – lines were observed in the alu-
minium samples after engraving. The quality of
lines – oriented surface, melted or non- oriented sur-
face depends on the laser beam parameters. It is suit-
able to make - samplers of tested materials.
The depth of tested engraved surface (created lines)
changes depending on the laser beam parameters,
but during onsetting, the surface (shape, depth and
width) keeps nearly the same dimensions and qual-
ity.
We measured the roughness of the originally tested
sample and the roughness of tested elds and the
characteristics of roughness proles werechanging
with laser parameters, but in the same eld, the
roughness prole had nearly the same course except
at the beginning of the rst line after laser marking
of the material.
We checked the state at the borders of the tested
elds (transition from the original surface to the
laser marking surface), as it can be seen in Figure 21
and Figure 22.The quality is satisfactory, without
specic melting or burning at the borders. Also it can
be seen in the sample in Figure 7 with various testing
elds.
When the number of laser runs across the tested
elds increased (from 2 to 10 times), we observed
larger thermal eect caused by re-melting of the sur-
face structure.
SEM microscope FEI QUANTA 400 with analyser EDAX
were used for detailed visualisation of tested samples,
where we conrmed that, by maintaining the settings of
laser parameters, the surface quality in a setting does not
change and has the same characteristics.
From the environmental point of view, we conrm that
the advantages of the laser marking are as follows:
Laser engraving technology is environmentally
friendly from the view of waste creation. Minimum
waste is produced during the operation. There are
no chips or lubrications as in the classical machin-
ing. In comparison with spraying, laser marking
does not need paints and other required media.
Laser graving operation terms very short time and
can be done on various shapes and surfaces of work-
pieces.
The inuence on the working environment is mini-
mal, because the operations are usually carried out
in closed cabins with dust extraction by lters and
pumps.
The thermal inuence of laser machine and noise
inuence areminimal as the working space is en-
closed.
Laser marking machines consume less electrical en-
ergy (e.g. only 0,45 KWh) in comparison with cutting
or welding, where the requirement is from 10 to 16
KWh.
After right set up, there is guarantee on the repeata-
bility of technology process. It can also be auto-
mated, which also reduce the errors and waste pro-
duction.
The disadvantage we see are in:
the price and service of the laser machines for small
enterprises,
training of sta - there is necessity for learned and
specialized workers,
the working environment must be protected, be-
cause of the creation of burned surfaces of parts.
The engraving laser method belongs to the new tech-
nology, which is used for describing dierent types of ma-
terials. The major advantages of this technology include
: a description of permanent good quality, non-contact
process (no tools required), minimal-waste treatment; no
need for clamped workpieces, low operating costs and
business process.
With simple programming the descriptions of serial
numbers, texts, barcodes, matrix codes, logos, brands and
various symbols can be done.
Acknowledgement: This work was supported by the
projects of the Ministry of Education, Science, Research
and Sport of the Slovak Republic KEGA 048TUKE- 4/2015
and VEGA 1/0537/15.
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... What makes this high-tech technology particularly attractive and contributes to their widespread use are the advantages of laser marking technology over other technologies: high productivity and low operating costs; easy to automate and integrate into production lines; high repeatability of the process associated with, high-quality brand; good accessibility, even in hard-to-reach places and even to uneven surfaces; no special working environment is required; contactless engraving and marking; precise beam positioning and highly localized energy transfer; minimum heat load, etc [1][2][3][4][5][6][7]. ...
... Distribution of laser technological processes in the industry in percentage. Adapted from[1]. CC BY-NC-ND 4.0. ...
... They concluded that a laser with 200 W and 1070 nm wavelength is unsuitable to fully melt a layer of powder on a solid layer of copper, even with a small spot size. This Laser absorption of copper as a function of (a) wavelength [30], (b) temperature [31]. ...
Article
The high electrical and thermal conductivities make copper the most suitable material for producing components where a high heat transfer capability is required. The material efficiency can be enhanced by designing shell and tube exchangers that allow high heat-transfer coefficient and high turbulence. However, high-performance design often required many manufacturing operations, including welding, that compromise the heat exchanger theoretical efficiency. Additive Manufacturing (AM) techniques can solve this problem definitely, but copper manufacturing is still particularly challenging for AM. Over the last decade, many studies have been carried out to face this topic and show possible solutions. This paper offers an overview of research advances on copper manufacturability via powder-based AM processes. The solutions are grouped into two categories: technological modifications and material modifications. This review highlights the best practices that may be considered for future works to accelerate the development of copper processed by AM. Overall, this work points out the importance, challenges and opportunities when the potentialities of AM processes are integrated with the unique characteristics of copper.
... In this type of marking, it is important to achieve the necessary contrast and to preserve the applied information throughout the working life of the detail [6][7][8][9]. This requires mandatory preliminary research of the type of technology in order to achieve the required quality of the marking in relation to the factors that affect the physics of the process [10][11][12]. The aim of the present study is to analyze the influence of specific technological parameters, such as power, processing speed and step between raster lines on the process of marking by a fiber laser with wavelength λ = 1640 nm on samples of polished black marble. ...
Article
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Over the last decade, laser surface treatment of stones has gained increasing scientific interest. New technologies and processes based on different types of laser sources and processing modes are being studied. This report examines the process of laser ablation of a marble surface using a fiber laser. Three factors influencing the process of laser marking and engraving were studied: laser power, processing speed and step between raster lines. The functional dependencies between these factors and the contrast of the obtained graphic image are established. The optimal operating intervals for this group of technological parameters are analyzed. Thanks to the very-high-definition laser ablation, inscriptions, drawings and images can be re-created and processed with unique accuracy. In addition, the reduction of manufacturing time and resources used in the process makes this technology an environmentally-friendly and extremely cost-efficient solution.
... There are also a few publications on the influence of the marking speed and step on the laser marking process [10,11,12]. ...
Article
Full-text available
Marking and engraving of aluminum was carried out by a CuBr (copper bromide) laser operating at the wavelength of 511 nm with a pulse duration of 30 ns. The reflection was investigated of the laser-ablated aluminum surface depending on the laser beam scanning speed and the distance between the laser lines. The changes of the aluminum surface were observed before and after laser processing by an optical microscope and visually. The laser marking quality was estimated by measuring the reflection of the irradiated aluminum surface by an optical spectrometer. The dependence was analyzed of the contrast on the speed for different steps in laser marking of areas of the surface of aluminum samples. Marking by a CuBr laser shows a potential for good quality marking of barcodes and QR codes on aluminum products.
... For many surfaces, laser marking can be used and it is the most cost effective option. Moreover, it often has a lower environmental impact that competing technologies [1]. One of the benefits of laser technology is that they use little or no added material to produce marks. ...
Conference Paper
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In this paper we present a novel method to print paper and cardboard without ink. The method is based on the carbonization of paper by a combination of lasers working on different wavelengths. A prove of concept system is created based on combining existing commercial systems to demonstrate the viability of the method. The results show that no debris is generated and the quality of the mark is superior in terms of contrast and resolution with previously known methods.
... The rapid development of laser technology makes it widely used in metal processing [1][2][3][4][5]. Laser coloring is a kind of surface irradiation technology that makes use of pyrolysis reaction to make the metal matrix react with surrounding gas at high temperature and produces metal oxide [6]. ...
Thesis
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Context: The increasing social awareness of environmental problems is demanding the industry to enforce sustainable strategies, including moving towards a Circular Economy. In order to apply this circularity to supply chains, Reverse Logistics is needed. It describes the process that manages the flow of unusable materials from the customer to the remanufacturing point. Notwithstanding its economic and environmen- tal opportunities, industries are still struggling with its implementation. Objective: The aim of this work is to analyse the difficulties and potentials of Reverse Logistics, focusing on technical aspects. Through the evaluation of identification sys- tems and modern trends, it seeks to overcome the challenges faced by the industry. Method: The results are obtained through a literature research on both founding and more recent contributions concerning Reverse Logistics. Results: Due to the uncertainties concerning quality, quantity, the time of returning products, and the costs linked to the implementation of a Reverse Logistics network, it is challenging for companies to motivate the investment in this solution. In addition, missing support from legislations and a lack of knowledge about the topic add to this difficulty. Nevertheless, through the appropriate use of identification systems and new technologies, it is possible to effectively use returned items and save costs on produc- tion processes. The implementation of Reverse Logistics would allow to decrease waste production and thus landfill, reduce emissions and maximise utility of natural resources. Conclusion: Possible solutions to overcome the challenges of Reverse Logistics can be achieved through the implementation of the appropriate Identification systems and a further development of technologies such as IoT, Blockchain, and AI. In order to encourage industries to introduce Reverse Logistics, a stronger political and techno- logical contribution is needed. Keywords: Reverse Logistics, Closed Loop Supply Chain, Auto-ID, RFID, SRSC
Article
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Quality issues caused by casting defects are commonly complicated to solve, because the part-specific process parameters are not traced to the individual cast part. This problem can be mitigated by the traceability of each cast part with an identifier code. Therefore, a study of the influence of marked surface topography and post-treatments on code symbol quality is desirable for a well-designed traceability system. In this work, the code symbol quality of laser, dot peen, and electrolytic marking methods on three as-cast surfaces of Al–Si alloy, after sandblasting and heat treatment, is evaluated comparatively with a customized image processing software. The result shows that the laser marking method produces the highest performance for different as-cast surfaces; electrolytic marking provides acceptable results only on the smooth surfaces of high-pressure die casting; dot peen marking produces the codes of high symbol contrasts, which are similar to those of laser marking, especially for rough as-cast surfaces of sand casting. However, for all marking methods, the code qualities of all surface topographies decrease substantially after post-treatments. Considering that dot peen marking has satisfying performances as well as low equipment and maintenance costs, this method is more suitable for small- and medium-size foundries to start to trace each cast part in an economical manner.
Article
The study is about the process of laser marking by melting products made of carbon structural steel 15Cr2 with wide application in industry. A fibre laser operating in the near-infrared region was used to perform the experiments. A raster marking method was used by varying the power density of the laser radiation and the frequency of pulses repetition. For each marked area, the contrast is determined by measuring the saturation of the marked area and the background by the greyscale. Graphs of the dependence of the contrast on the power density for three marking speeds and on the contrast on the frequency for two marking speeds are analysed. The work intervals for the power density and frequency for this steel and fibre laser, are determined.
Article
Full-text available
The paper deals with the evaluation of relation between roughness parameters of Ti6Al4V alloy produced by DMLS and modified by abrasive blasting. There were two types of blasting abrasives that were used – white corundum and Zirblast at three levels of air pressure. The effect of pressure on the value of individual roughness parameters and an influence of blasting media on the parameters for samples blasted by white corundum and Zirblast were evaluated by ANOVA. Based on the measured values, the correlation matrix was set and the standard of correlation statistic importance between the monitored parameters was determined from it. The correlation coefficient was also set.
Article
Full-text available
In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.
Article
The contribution deals with the implementation of new information from the area of laser marking processing. The marking of various types of metal and non-metal materials are very actual topic of these days. The focus is on the production technical aspects of laser engraving and the introduction of processing strategies. Less attention is paid to the complex chemical process that can be observed when using laser as a tool chance the visible material appearance. The aim is to identify the parameters and guidelines that can be used to control the laser engraving process in the production environment. The problem of engraved metal material surface is discussed in solved experiments. The aim of the contribution is visual and microscope evaluation, how by changing of laser parameters can chance the influence on the final visage of tested metallic materials.
Article
The use of short and ultrashort laser pulses for micromachining application is an emerging technology. Laser Beam MicroMachining (LBMM) has revolutionized many industries by providing innovative solutions in numerous industrial micro-engineering applications. High-intensity short or ultrashort laser pulses are powerful thermal energy source for creating micro-features in wide range of materials. These lasers can precisely ablate various types of materials with little or no collateral damage. An overview of LBMM is given so that we can obtain a current view of capabilities and tradeoffs associated with LBMM of sub-micron size. The fundamental understanding of ultrafast laser ablation process has been elucidated and the various research activities performed with nanosecond, picosecond and femtosecond, lasers have been discussed to understand the physical mechanisms and the critical experimental parameters involved in the LBMM. The critical analysis of various theoretical and experimental models used to describe the performance analysis of LBMM has been elaborated so that we can identify the relevant principles underlying the process.
Article
The characteristics of the materials laser marking concerning its productivity, flexibility and quality obtained, led to an industrial implementation of this technique. Based on the vaporizing, melting or colour changing of the irradiated material, laser marking is well adapted for all types of materials. The paper presents different marking methods, revealing the advantages of laser marking versus other marking technologies. The mechanism and the quality characteristics of the materials laser marking technologies are also presented.
Laser beam machining, Non-traditional machining process
  • M Brandt
  • S Sun
Brandt M., Sun S., Laser beam machining, Non-traditional machining process, London, Springer, 2013
Environmentálne merania a monitoring v strojárstve (Environmental measuring and monitoring in Manufacturing), 1st
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Kralikova R., Badida M., Environmentálne merania a monitoring v strojárstve (Environmental measuring and monitoring in Manufacturing), 1st.ed., Reprocentrum, Košice, 2010
How to choose the best laser for your marking application
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Kaminski D., Laser Marking. How to choose the best laser for your marking application, Laserfocusworld 2011, http://www.laserfocusworld.com/articles/2011/04/lasermarking-how-to-choose-the-best-laser-for-your-markingapplication.html
The laser as a tool, 1st
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Buchfink, G., The laser as a tool, 1st.ed, Rosler Druck GmbH, Schondorf, 2007,
Engraving of materials How to choose the best laser for your marking application
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  • D Kaminski
  • Laser Marking
Trumpf Slovakia, s.r.o., Engraving of materials, 2015, www.sk.trumpf.com [7] Kaminski D., Laser Marking. How to choose the best laser for your marking application, Laserfocusworld 2011, http://www.laserfocusworld.com/articles/2011/04/lasermarking-how-to-choose-the-best-laser-for-your-markingapplication.html