(1)Causes of black explosion points When the laser passes through the stain, a violent oxidation reaction will occur to form gas, which will directly affect the stability of the molten pool keyhole and form a black explosion point. Specifically, the molten pool keyhole is abnormally closed, resulting in insufficient melting depth, insufficient melting width, unmelted surface or direct penetration of the parent material, which requires metallographic cutting to assist in judgment.

From the manufacture of energy storage battery cells to the assembly of battery PACKs, welding is a very important manufacturing process. The conductivity, strength, air tightness, metal fatigue and corrosion resistance of lithium batteries are typical battery welding quality evaluation standards. The selection of welding methods and welding processes will directly affect the cost, quality, safety and consistency of the battery.

Fiber laser is a laser that uses optical fiber to amplify and transmit the generated excitation light, and has a wavelength of 1070nm that is easily absorbed by metals. Among many lasers, it has a particularly high energy density and has the characteristics of easy convergence of the beam, and its major advantage is that it can achieve deep melting of metals. Compared with YAG laser, it has many advantages such as deep melting, low running cost, and almost no trouble and cost for adjustment and maintenance, and its popularity has accelerated in recent years. Although fiber laser has the characteristics of high power and high efficiency, if the power is too high in manual welding of sheet metal, it will cause danger to the operator, so the power is usually limited to about 1kW when making products. When pursuing higher power and greater penetration depth, mechanical welding and robot welding can be studied.

Why use a flat-top laser beam?