Laser cutting as we all know is a very common method of cutting that is used quite commonly to cut many materials for several applications. There are several different methods of cutting using a laser to cut varied kinds of materials. Some of the different laser cutting methods are – vaporisation, melt, melt and blow, thermal stress, blow and burn, cold cutting, cracking, scribing and burning stabilised laser cutting. Let’s take a more in-depth look at some of the methods of laser cutting, below.
In the process of vaporised cutting, a focused laser beam heats the material surface to its boiling point and makes a keyhole. The keyhole increases the absorption of electromagnetic radiation and deepens the hole quickly. As the hole becomes deeper, the material begins to boil and the vapour that is generated causes the molten walls to erode and blows the molten material out causing the hole to enlarge further. Non-melting materials like carbon, wood and thermoset plastics are usually cut using this method.
Melt and blow, also known as fusion cutting, makes use of gas at high pressure that blows away the molten material from the cutting area. This helps to reduce the power requirement considerably. The material is first heated to its melting point and a gas jet is used to blow the molten material out from the kerf. This avoids the requirement of raising the temperature of the material further. Metals are usually cut using the method of melt and blow.
Thermal Stress Cracking makes use of the property of brittle materials that are sensitive to thermal fracture when exposed to heat. A laser beam is focussed on the surface of the material, which causes localised heating and thermal expansion. This causes a crack in the material, which is then guided by moving the laser beam. This process is usually used in cutting glass.
This method is also called flame cutting or burning stabilised laser gas cutting. In the process of reactive cutting, the cutting process is very similar to oxygen torch cutting, but here a laser beam is used as the ignition source instead. Reactive cutting is used to cut carbon steel of a thickness of 1mm or more. This cutting process can be used for very thick steel plates using comparatively less laser power.
In the semiconductor fabrication process, the microelectronic chips are separated from silicon wafers using the process of stealth dicing, which is usually done using a pulsed Nd:YAG laser.
There are several methods of laser cutting and you must decide on the best method that will suit your fabrication and cutting requirements, and result in the best efficiency and productivity for your cutting application and business.