Laser cutting – metal laser cutting

Laser cutting is a technology that uses a laser to cut materials, and is typically used for industrial manufacturing applications. Laser cutting works by directing the output of a high-power laser most commonly through optics. Industrial laser cutters are used to cut flat-sheet material as well as structural and piping materials.

Laser cutting – metal laser cutting

Types of laser cutting

CO2 lasers are commonly "pumped" by passing a current through the gas mix (DC-excited) or using radio frequency energy (RF-excited). The RF method is newer and has become more popular. Since DC designs require electrodes inside the cavity, they can encounter electrode erosion and plating of electrode material on glassware and optics. Since RF resonators have external electrodes they are not prone to those problems. CO2 lasers are used for industrial cutting of many materials including titanium, stainless steel, mild steel, aluminium, plastic, wood, engineered wood, or paper. These lasers are primarily used for cutting and scribing metals and ceramics.

In addition to the power source, the type of gas flow can affect performance as well. Common variants of CO2 lasers include fast axial flow, slow axial flow, transverse flow, and slab. In a fast axial flow resonator, the mixture of carbon dioxide, helium and nitrogen is circulated at high velocity by a turbine or blower. Transverse flow lasers circulate the gas mix at a lower velocity, requiring a simpler blower. Slab or diffusion cooled resonators have a static gas field that requires no pressurization or glassware, leading to savings on replacement turbines and glassware.

The laser generator and external optics (including the focus lens) require cooling. Depending on system size and configuration, waste heat may be transferred by a coolant or directly to air. Water is a commonly used coolant, usually circulated through a chiller or heat transfer system.

A laser microjet is a water-jet guided laser in which a pulsed laser beam is coupled into a low-pressure water jet. This is used to perform laser cutting functions while using the water jet to guide the laser beam, much like an optical fiber, through total internal reflection. The advantages of this are that the water also removes debris and cools the material. Additional advantages over traditional "dry" laser cutting are high dicing speeds, parallel kerf, and omnidirectional cutting.

Fiber lasers are a type of solid state laser that is rapidly growing within the metal cutting industry. Unlike CO2, Fiber technology utilizes a solid gain medium, as opposed to a gas or liquid. The “MAG laser” produces the laser beam and is then amplified within a glass fiber. With a wavelength of only 1.064 micrometers fiber lasers produce an extremely small spot size (up to 100 times smaller compared to the CO2) making it ideal for cutting reflective metal material. This is one of the main advantages of Fiber compared to C2.

 

Laser cutting methods

There are many different methods in cutting using lasers, with different types used to cut different material. Some of the methods are vaporization, melt and blow, melt blow and burn, thermal stress cracking, scribing, cold cutting and burning stabilized laser cutting.

 

Vaporization cutting

In vaporization cutting the focused beam heats the surface of the material to boiling point and generates a keyhole. The keyhole leads to a sudden increase in absorptivity quickly deepening the hole. As the hole deepens and the material boils, vapour generated erodes the molten walls blowing ejecta out and further enlarging the hole. Non melting material such as wood, carbon and thermoset plastics are usually cut by this method.

Melt and blow

Melt and blow or fusion cutting uses high-pressure gas to blow molten material from the cutting area, greatly decreasing the power requirement. First the material is heated to melting point then a gas jet blows the molten material out of the kerf avoiding the need to raise the temperature of the material any further. Materials cut with this process are usually metals.

Thermal stress cracking

Brittle materials are particularly sensitive to thermal fracture, a feature exploited in thermal stress cracking. A beam is focused on the surface causing localized heating and thermal expansion. This results in a crack that can then be guided by moving the beam. The crack can be moved in order of m/s. It is usually used in cutting of glass.

Stealth dicing of silicon wafers

The separation of microelectronic chips as prepared in semiconductor device fabrication from silicon wafers may be performed by the so-called stealth dicing process, which operates with a pulsed YAG laser, the wavelength of which is 1064 nm.

Reactive cutting (burning stabilized laser gas cutting, flame cutting)

Reactive cutting is like oxygen torch cutting but with a laser beam as the ignition source. Mostly used for cutting carbon steel in thicknesses over 1 mm. This process can be used to cut very thick steel plates with relatively little laser power.

 

Laser cutting in Nyíregyháza

 In addition to the elevators, our company is engaged in sheet metal working as well.

For the present, our general activities include: sheet metal working: laser cutting, CNC bending, CNC die cutting, CNC punching, CNC cutting, manufacture of unique metal structures, metalwork, furthermore:

  • Powder coating;
  • Grit blasting, surface cleaning;
  •  Manufacture of products in series;
  • Riveting, and:

Our company undertakes to perform contract manufacturing of metal products in small, medium and large series, from machining of blank metal products to laser cutting, bending, cutting, metalwork, surface finishing as well as packaging and delivery. Beyond the standard black sheet, stainless steel or galvanised sheet, the products to be machined may be more unique as well (copper, coloured stainless steel, aluminium, etc.).

In addition to inquiries for simple CNC sheet cutting or laser cutting, powder coating, maybe CNC bending, you can ask offer from us for complete metalwork structures such as control cabinets, fences in accordance with specifications. Customer satisfaction is ensured by our quality department with proper measuring devices.

If you inquire for manufacturing in large series but for the present we do not have the proper special machine or tool partially or fully, then for establishing long-term work relationship (or depending on the size of the single order) we can even extend our machine park within the framework of a separate project in accordance with the client’s demands.

Please see introduction of our company and if you have such demand please do not hesitate to contact us via one of the following addresses.