Laser marking machine marking belongs to non-contact marking. In this marking process, there will be an interaction. Generally speaking, it is a microscopic quantum process, including laser reflection, absorption, diffraction, interference, polarization, photoelectric effect, and gas shock. Wait, if we understand the structure of the laser marking machine, these are easy to understand. We usually say that the laser marking machine marking on the product material is a physical process, which is essentially the interaction between the electromagnetic field and the material structure, that is, the process of resonance interaction and energy conversion. When a beam of laser light hits the metal surface, with The prolongation of the irradiation time will cause a series of physical and chemical changes on the surface and inside of the metal. This process is called a laser marking machine to mark on the product material, so we know that the laser marking machine marks on the product It is not necessary that only physical reactions take place or also chemical reactions take place. The laser marking machine also undergoes impact strengthening process, heat absorption process, surface melting process, vaporization process and composite process during marking.
The impact strengthening process refers to the process of strengthening the surface of the material by generating local pressure on the surface of the material when the energy of the laser in the continuous pulse laser marking machine is too high and the action time is short. The heat absorption process means that the laser beam is irradiated on the surface of the material. In addition to the part of the heat lost by scattering and reflection, a large number of photons are converted into heat energy through the interaction of the metal lattice to make it vibrate. The efficiency of energy conversion is related to the material structure, laser wavelength, etc. have this close relationship. During the surface melting process, the light energy is continuously transformed into heat energy, and the surface temperature of the material continues to rise. When the temperature exceeds the melting point of the material, the surface of the material begins to melt. With the delay of time, the heat-affected zone will continue to spread to the inside, and the molten pool will also think of the inside. Development, note belongs to cold processing laser equipment.
Vaporization process When the intensity and density of the laser beam are high enough, vaporization and plasma radiation can be generated on the surface of the material. With the extension of laser irradiation time, the surface of the molten pool will be vaporized, and plasma will start to be generated, forming surface ablation. In the composite process, under the irradiation of the laser marking machine, the surface of the ultraviolet laser marking machine will form vapors and plasma sputtering and reverse radiation will shield the incident light. If the irradiation continues and certain conditions are met , then the shielding effect begins to weaken and form automatic adjustment and absorption, that is, a self-sustaining adjustment state, and these processes are completed within picosecond or microsecond time. When the laser marking machine marks and marks the material, a series of processes will occur with the material. This series of processes is called physical reaction or chemical reaction with the material.
First, the directionality of the laser marking machine. Laser marking machines generally propagate along the axis, and the beam divergence angle is very small. The principle is that the smaller the beam divergence angle, the better the directionality of the beam. The high directivity of the laser marking machine is mainly caused by the stimulated emission mechanism. Determined by the limitation of the optical resonator on the direction of the oscillating beam, the directionality of the laser marking machine can be transmitted for a long distance, and can be focused to a very high power density, so that the product can be marked and marked. Second, the monochromaticity of the laser marking machine.
If the width of the spectral line emitted by the laser marking machine is smaller, its color will be purer, the marking mark will be more obvious, and the monochromaticity of the light source will be better. The monochromaticity of the standard machine is extremely high, almost completely eliminating the dispersion effect of the focusing lens, so that the beam can be precisely focused on the focal point, and a high power density is obtained. Three, the coherent light intensity of the laser marking machine. The laser marking machine correlation mainly describes the wavelength of the laser light source, and the laser processing wavelength has 1064μm, 355μm, etc., the coherence of laser marking machine is divided into time coherence and space coherence. Time coherence is the phase relationship of each point along the beam propagation direction. In actual work of laser marking machine, coherence time is often used to describe laser Generally speaking, the narrower the bandwidth of the spectral line, that is, the higher the monochromaticity, the longer the coherence time. Spatial coherence is the phase relationship between points on the plane perpendicular to the beam propagation direction, which refers to The light emitted by the beam within a certain size range can form an interference phenomenon when it is combined in a certain place in space. The spatial coherence is related to the size of the light source. If the spatial correlation is to be improved, the working mode of the laser should be limited first, and the type of optical cavity should be selected reasonably And increase the cavity length to improve beam directivity.
Zhuhai Correct Pack is a well-known laser equipment manufacturer in China. It has been focusing on the development and production of laser equipment for 12 years, providing customers with a complete set of laser equipment solutions, and creating cost-effective laser equipment. Main business: UV, co2, fiber laser marking machines, laser radium engraving machines And other cost-effective laser equipment, national service hotline: 400-0098-266https://www.xmslaser.com/.