Laser Welding
Using lasers is the most advanced and accurate welding process that uses a beam to connect two or more pieces of metal together by melting the edge areas, which resolidify together to form one piece. This process can be performed in open air or a tube, and creates fusion welds, which don't use any sort of filler material to join the two pieces. The aerospace, military and defense, electronics, lab research, medical and petrochemical industries use laser welding because it's a fast process that offers minimized heat input and deep penetration abilities. Two types of lasers are used for laser welding-CO2 gas lasers and neodymium-doped yttrium aluminum garnet lasers, often referred to as solid state lasers. While gas lasers are faster, they also have more issues with reflective materials like copper.
The laser welding process starts with choosing the focal point target on the material's surface. The laser is converted into thermal energy at the surface, and the material begins to melt. Generally, the material being welded is less than .8 inches in order to obtain the best metallurgical and physical characteristics available. The laser always passes through a focusing lens because it concentrates the beam energy to an extremely small and precise focal point. The melted areas of each piece of material are joined together and fuse upon cooling. The welds made by lasers can be deep, narrow, small or thin, and distortion is rarely if ever an issue.