OFweek Laser
News: With the development of application of laser technology, print a variety
of eye-catching bright colors on stainless steel by laser, this application has
been gradually coming into view. These seemingly ethereal fantasy colors, are
there any regularity to track? How to adjust the parameters to get the desired
color quickly? Is there any requirement on the application of the laser light
source ?
Stainless steel
color principle
The human eye is
able to distinguish between a variety of different colors, in fact, because
when the light shines on the surface, the reflected light of different
wavelengths, these different wavelengths of light are captured visually cells
through the brain processing resolution, it creates different colors feeling.
This return to a stainless steel material, only after a laser treatment can be
of various colors, the truth is the same.
From the
physical properties of stainless steel to analyze the principles of color,
stainless steels are nothing more than change before and after the laser
processing in three ways: First, to form a colored oxide; the second is by
chemically, electrochemically or laser role in generating a stainless steel
surface colorless, transparent oxide film layer is extremely thin oxide film to
produce an interference effect, the surface may show color; the third is at the
same time there is a mixed state colored oxide and oxide film.
MOPA laser
marking color on stainless steel
MOPA laser's
advantage lies in its width and frequency independently adjustable, adjust one
does not affect the other laser parameters, this is the Q-switch lasers are not
available. The MOPA structure feature, the color marking for stainless steel
with infinite possibilities. In actual operation, marking these factors pulse
width, frequency, power, speed, fill mode, fill spacing, delay parameters will
affect the color effects. The impact of these parameters will cause a color
change feature is not unique, but are interrelated and influence each other.
Have mentioned
before, pulse width and frequency are characteristic MOPA lasers, mutually
independently adjustable; and, these two parameters in stainless steel color
play on two parameters is also the most distinctive, mutual cooperation between
them, can be adjusted a colorful world. Today, the protagonist of our story
presentation, is one of them, as well as a marking auxiliary parameters -
frequency and power.
Speaking of
power, it's not strange, it is able to influence the most important single
laser pulse output most intuitive control variables. After testing found that
when playing in stainless steel color, frequency and pulse width in a
"contest", the parameters affect the frequency of color changes in
some of the richer. If the frequency and power together, under certain
conditions, such a law will appear the following: In the densely populated
pitch, medium width, high-frequency (fill spacing <0.005mm; pulse width
45ns-100ns; frequency ≥300kHZ) of case, the power is increased by a small, stainless steel
manifested in color showing very regular variation: yellow, red, blue, green,
until the green gradually become darker. As shown below (@ 60ns, 0.001mm
arcuate padding, F = 163mm field lens)
(Lateral power
of 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%)As can be seen from the chart,
with the frequency of the power changes, color changes show a certain
regularity. This change in regular is filled pitch, the same applies. As shown
below (@ 60ns, 0.005mm arcuate padding, F = 163mm field lens)
(Lateral power
of 30%, 35%, 40%, 45%, 50%, 55%, 60%)At this point you can see, the premise of
densely packed pitch, medium width, high-frequency, changes in the filling of
the corresponding color change effect appear smaller, and more color change is
caused by the frequency and power brought about by the action. In other words,
the difference in color, mainly influenced by the laser pulse energy itself and
its overlapping spot rate on steel, and stainless steel reaction to the color
mode of going, is showing a picture as seen on the regular changes. Impact on
the frequency and power of color changes described in this article, although
not representative of the whole process of playing color color features, but in
marking applications, but also in a certain range of parameters, and to provide
some reference value .
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