1、汽化切割。在高功率密度激光束的加热下，材料表面温度升至沸点温度的速

1、汽化切割。<br>在高功率密度激光束的加热下，材料表面温度升至沸点温度的速度是如此之快，足以避免热传导造成的熔化，于是部分材料汽化成蒸汽消失，部分材料作为喷出物从切缝底部被辅助气体流吹走。<br> 2、熔化切割。<br>当入射的激光束功率密度超过某一值后，光束照射点处材料内部开蒸始发，形成孔洞。一旦这种小孔形成，它将作为黑体吸收所有的入射光束能量。小孔被熔化金属壁所包围，然后，与光束同轴的辅助气流把孔洞周围的熔融材料带走。随着工件移动，小孔按切割方向同步横移形成一条切缝。激光束继续沿着这条缝的前沿照射，熔化材料持续或脉动地从缝内被吹走。<br> 3、氧化熔化切割。<br>熔化切割一般使用惰性气体，如果代之以氧气或其它活性气体，材料在激光束的照射下被点燃，与氧气发生激烈的化学反应而产生另一热源，称为氧化熔化切割。<br> 4、控制断裂切割。<br>对于容易受热破坏的脆性材料，通过激光束加热进行高速、可控的切断，称为控制断裂切割。这种切割过程主要内容是：激光束加热脆性材料小块区域，引起该区域大的热梯度和严重的机械变形，导致材料形成裂缝。只要保持均衡的加热梯度，激光束可引导裂缝在任何需要的方向产生。

1. Vaporization cutting.<br>Under the heating of high power density laser beam, the speed of the material surface temperature rising to the boiling point temperature is so fast that it is enough to avoid melting caused by heat conduction. Therefore, some materials vaporize into steam and disappear, and some materials are blown away from the bottom of the slit as ejecta by the auxiliary gas flow.<br>2. Melt cutting.<br>When the power density of the incident laser beam exceeds a certain value, the evaporation inside the material at the beam irradiation point begins to form holes. Once this small hole is formed, it will absorb all the incident beam energy as a blackbody. The small hole is surrounded by the molten metal wall, and then the auxiliary air flow coaxial with the light beam takes away the molten material around the hole. As the workpiece moves, the small hole moves transversely synchronously according to the cutting direction to form a cutting seam. The laser beam continues to irradiate along the leading edge of the seam, and the molten material is blown away from the seam continuously or Pulsatively.<br>3. Oxidation melting cutting.<br>Melting cutting generally uses inert gas. If oxygen or other active gas is replaced, the material will be ignited under the irradiation of laser beam, and another heat source will be generated by fierce chemical reaction with oxygen, which is called oxidation melting cutting.<br>4. Control fracture cutting.<br>For brittle materials that are easy to be damaged by heat, high-speed and controllable cutting by laser beam heating is called controlled fracture cutting. The main content of this cutting process is: the laser beam heats a small area of brittle material, resulting in large thermal gradient and serious mechanical deformation, resulting in the formation of cracks in the material. As long as a uniform heating gradient is maintained, the laser beam can guide the crack in any desired direction.

1. Vaporization cutting. Under the heating of high power density laser beam, the surface temperature of the material rises to the boiling point temperature so fast that it can avoid the melting caused by heat conduction, so that part of the material evaporates into steam and disappears, and part of the material is blown away by the auxiliary gas flow from the bottom of the slit as a jet. 2. Melting and cutting. When the power density of the incident laser beam exceeds a certain value, the internal steaming of the material at the irradiation point of the laser beam starts, forming holes. Once the hole is formed, it will act as a black body to absorb all the energy of the incident beam. The hole is surrounded by the molten metal wall, and then, the auxiliary gas flow coaxial with the light beam takes away the molten material around the hole. As the workpiece moves, the small hole moves synchronously along the cutting direction to form a slit. The laser beam continues to irradiate along the front edge of the seam, and the molten material is continuously or pulsately blown away from the seam. 3. Oxidation, melting and cutting. Generally, inert gas is used for melting. If oxygen or other active gas is used instead, the material will be ignited under the irradiation of laser beam, and it will react violently with oxygen to generate another heat source, which is called oxidative melting cutting. 4. Control fracture cutting. For brittle materials easily damaged by heat, high-speed and controllable cutting by laser beam heating is called controlled fracture cutting. The main content of this cutting process is that the laser beam heats a small area of brittle material, causing large thermal gradient and severe mechanical deformation in this area, which leads to cracks in the material. As long as a balanced heating gradient is maintained, the laser beam can guide cracks to be generated in any desired direction.