Laser—— Laser Beam Welding

There are two forms of laser welding according to the power density hit on workpiece,heat conduction welding and keyhole welding.The heat conduction welding process occurs when the power density is typically less than 10⁵W/cm².In this type, the metal surface is heated above the melting point of metal,but not to the extent that it vaporizes.The heat of laser beam was absorbed and conducted into inner of metal to melt metal. Keyhole welding is used require high power density, typically over 10⁵W/cm².With higher power densities , the laser beam simultaneously melts and evaporates the metal surface while conductors absorb excess heat.The laser beam penetrates the workpiece forming a keyhole cavity. As the laser travels across cavity, achieving deep welds,resulting in excellent depth to width ratio and weld cap with a chevron pattern.