Vaporization cutting Under the heating of the high power density laser beam, the surface temperature of the material rises to the boiling point temperature so fast that it avoids the melting caused by heat conduction, so that some of the material vaporizes into vapor and some of the material is ejected from the bottom of the slit. The auxiliary gas stream is blown away. Some materials that cannot be melted, such as wood, carbon materials and certain plastics, are cut and formed by this vaporization cutting method. During the vaporization and cutting process, the steam carries away the molten particles and washes the debris to form holes. During vaporization, approximately 40% of the material is vaporized, while 60% of the material is removed by airflow in the form of droplets. Melt cutting When the incident laser beam power density exceeds a certain value, the inside of the material at the beam irradiation point begins to evaporate, forming a hole. Once such a small hole is formed, it will absorb all of the incident beam energy as a black body. The aperture is surrounded by the molten metal wall and then an auxiliary gas stream coaxial with the beam carries away the molten material around the hole. As the workpiece moves, the small holes are simultaneously traversed in the cutting direction to form a slit. The laser beam continues to illuminate along the leading edge of the slit, and the molten material is blown away from the slit continuously or pulsatingly. Oxidative melt cutting Melting and cutting generally uses an inert gas. If it is replaced by oxygen or other reactive gas, the material is ignited under the irradiation of a laser beam, and a strong chemical reaction with oxygen produces another heat source called oxidative melting cutting. The specific description is as follows: (1) The surface of the material is quickly heated to the ignition temperature under the irradiation of the laser beam, and then a severe combustion reaction with oxygen is performed to release a large amount of heat. Under the action of this heat, a small hole filled with steam is formed inside the material, and the periphery of the small hole is surrounded by a molten metal wall. (2) The combustion material is transferred into slag to control the burning speed of oxygen and metal, and the speed at which oxygen diffuses through the slag to reach the ignition front also has a great influence on the burning speed. The higher the oxygen flow rate, the faster the combustion of the chemical reaction and the removal of the slag. Of course, the higher the oxygen flow rate, the better, because too fast a flow rate will result in rapid cooling of the reaction product at the exit of the slit, the metal oxide, which is also detrimental to the quality of the cut. (3) Obviously, there are two heat sources in the oxidative melting and cutting process, namely the laser irradiation energy and the thermal energy generated by the chemical reaction between oxygen and metal. It is estimated that when cutting steel, the heat released by the oxidation reaction accounts for about 60% of the total energy required for cutting. It is apparent that the use of oxygen as an auxiliary gas results in a higher cutting speed than an inert gas. (4) In the oxidative melting cutting process with two heat sources, if the burning speed of oxygen is higher than the moving speed of the laser beam, the slits appear wide and rough. If the laser beam moves faster than oxygen, the resulting slit is narrow and smooth. Controlled fracture cutting For brittle materials that are easily damaged by heat, high-speed, controlled cutting by laser beam heating is called controlled fracture cutting. The main content of this cutting process is that the laser beam heats the small area of ​​the brittle material, causing a large thermal gradient and severe mechanical deformation in the area, resulting in the formation of cracks in the material. As long as a balanced heating gradient is maintained, the laser beam can direct the crack to occur in any desired direction. It should be noted that this controlled fracture cutting is not suitable for cutting acute and angular slits. Cutting a large closed shape is also not easy to succeed. Control the fracture cutting speed is fast, do not need too high power, otherwise it will cause the surface of the workpiece to melt and damage the edge of the slit. The main control parameters are laser power and spot size. (end) Concerned about surprises Label: droplets laser cutting laser beam slitting carbon material Previous: Common faults and solutions for lamp-pumped laser marking machines Next: Laser cutting machine maintenance Common types and uses of pliers Wire Stripper,Needle-Nose Pliers,Wire Cutters,Curved Nose Pliers Rugao Yaou Import & Export Trade Co., Ltd , https://www.ntyaous.com
Pliers have many functions and are used in many industries. The pliers used in different industries are also different. Generally, the more commonly used pliers are:
1. Wire stripper
Wire strippers are commonly used tools for internal electricians, motor repairs, and instrumentation electricians. They are composed of knife edges, crimping ports and clamp handles. They are mainly used for stripping plastic and rubber insulated wires and cable core wires.
2. Wire cutters
Also called a vise, it is a kind of clamp and cutting tool. It is composed of jaws, tooth edges, knife edges, guillotines and pliers handles. It is mostly used to pick up nails or break nails and iron wires.
3. Nozzle pliers
It can be divided into electrical and electronic categories. It is mainly used for cutting injection molding machine products, plastic products, and injection nozzles. It is also suitable for cutting metal products and electronic component pins.
4. Needle-nose pliers
Also known as trimmers, pointed pliers, and pointed pliers. They are composed of pointed tips, knife edges and pliers handles. They are generally made of 45# steel. They are used to cut single and multi-strand wires with thinner diameters and to give orders. Stranded wire joint bending, stripping of plastic insulation layer, etc., can be operated in a relatively small working space.
5. Curved nose pliers
Also called elbow pliers, its function is similar to that of needle-nose pliers without cutting edge, and it is suitable for use in narrow or recessed working spaces.
6. Flat nose pliers
It is a commonly used tool for assembly of metal parts and telecommunications engineering. It is generally used to bend metal sheets and metal filaments to make them into the required shape. In repair work, they are used to install and pull out pins, springs, etc.
7. Diagonal pliers
Mainly used to cut metal wires, flat-nose diagonal pliers are suitable for use in recessed working spaces.
8. Top cutting pliers
End-cutting pliers are similar to diagonal pliers. They are mainly used for cutting steel wires with the cutting edge at the top.
9. Water Pump pliers
The function is similar to a pipe wrench, but it is lighter, smaller and easier to use than a pipe wrench. However, the clamping force is not as good as a pipe wrench. Generally, it is only suitable for household non-professional emergency or simple installation of water pipes.
10. Slip joint pliers
The shape resembles a carp. The opening width of the jaws has two adjustment positions, which can be enlarged or reduced. It is mainly used to clamp round parts. It can also replace small nuts and small bolts with a wrench. It is often used in the auto repair industry.
11. Circlip pliers
Commonly known as circlip pliers, it is a special tool used to install inner and outer circlips, and can also be used to remove circlips. .
12. Vigorous pliers
It is mainly used for clamping parts for riveting, welding, grinding, etc. It can also be used as a wrench. Its characteristic is that the jaws can be locked and generate a large clamping force to prevent the clamped parts from loosening.