Pulse width and frequency are the characteristics of MOPA laser, which are independent and adjustable; Moreover, these two parameters are also the most characteristic parameters of laser marking machine in stainless steel color marking. Their mutual cooperation can call out a colorful world. The protagonist of our story today is one of them and an auxiliary parameter of marking – frequency and power.
Speaking of power, you must be familiar with it. It is the most important and intuitive control variable that can affect the laser single pulse output. After testing, it is found that when stainless steel is colored, the frequency is “competing” with the pulse width, and the influence of the parameter frequency on the color change is richer. If the frequency and power are put together, the following laws will appear under some conditions: in the case of dense filling spacing, medium pulse width and high frequency (filling spacing < 0.005mm; pulse width 45ns-100ns; frequency ≥ 300kHz), the power increases from small, and the color on stainless steel shows very regular change characteristics: yellow, red and blue, Green until the green turns dark.
So far, it can be seen that on the premise of dense filling spacing, medium pulse width and high frequency, the change of filling has less effect on the change of color, and more color changes are caused by frequency and power. In other words, these color differences are mainly affected by the single pulse energy of the laser itself and its spot overlap rate on the steel sheet, and are reflected in the color rendering mode of stainless steel.
In conclusion, the color marking of laser marking machine is the embodiment of its energy and density for the same material. Which is determined by the energy density.