There are various ways of separating materials. Mechanical method includes sheering, and thermal methods include oxyfuel, plasma, and laser cutting.
Welding process and appropriate gas usage go hand in hand.
Cutting
Supporting the full range of cutting processes with high-purity gases, bespoke mixtures, state-of-the-art equipment and supporting services.
In the case of oxyfuel, plasma and laser cutting, thermal energy is used to anneal materials up to ignition, melting or evaporation temperatures.
Oxyfuel cutting and laser cutting with oxygen use the exothermic energy of the oxygen reaction in the process. Flame and laser beam anneal materials only until ignition temperature is reached. The oxygen jet burns the material and blows out melt and slag.
The cutting speed depends on the purity of the oxygen and the shape of the cutting gas jet. High purity oxygen, optimised nozzle design and suitable gas supply means high productivity.
In plasma cutting and laser cutting with nitrogen, the material is annealed up to melting temperatures and the cutting gas blows out the melt. The nature of cutting gases needs to be adapted to application for best performance.
Lasers can also be used to evaporate materials such as wood or plastics. Evaporation of metallic material is used for example in laser drilling or piercing of the starting hole. Gases suppress ignition of flammable materials and support material removal during drilling and piercing.
Welding
As a joining method, welding has been around for centuries. Today, roughly 100 welding methods are used in different sectors of the industry. The use of industrial gases (whether as individual gases or gas mixtures) to optimise welding processes dates back to the 40s and 50s. Since then, the gas based welding processes have emerged to be the predominant group of welding methods.
Welding is an essential process in just about every industry. Various techniques are used to melt and fuse metals, steels and alloys.
Arc welding uses the heat generated by an electric arc struck between an electrode and a workpiece to melt and fuse metal in the joint area. This is the most common fusion-based joining method used in industry today.
However, laser welding is growing in popularity in the automotive industry in particular and in other sectors such as microelectronics and shipbuilding. This involves focusing a laser beam onto a workpiece by a set of mirrors. When the laser beam is moved relative to the workpiece, the energy of the focused laser beam melts the metal so that a joint is formed.
In all welding processes, the shielding and process gases, their exact compositions and their purity levels play a key role in influencing weld quality and productivity.