Manufacturing
Laser welding technology is widely used in foreign passenger car manufacturing. Statistics show that there were over 100 laser trimming blank welding production lines globally in 2000, producing 70 million car component welding blanks annually, with continued high-speed growth. Domestic production of imported models also employs some trimming blank structures. Japan has replaced flash butt welding with CO2 laser welding for connecting steel rolling sheets in the steel industry, demonstrating the vast potential of laser welding in ultra-thin plate welding research, such as foil sheets below 100 micrometers in thickness, which are unmeltable by conventional methods but successfully welded using YAG laser welding with a special output power waveform. Japan has also successfully developed the application of YAG laser welding for the repair of steam generator thin tubes in nuclear reactors for the first time in the world, and is also conducting gear laser welding technology domestically.
Powder Metallurgy
As science and technology continue to advance, many industrial technologies require special materials, and the materials produced by traditional casting and forging methods are no longer sufficient. Due to the unique properties and manufacturing advantages of powder metallurgy materials, they are replacing traditional casting materials in certain fields such as automotive, aviation, and tool cutting industries. With the increasing development of powder metallurgy materials, the issue of their connection with other parts has become increasingly prominent, limiting their application. In the early 1980s, laser welding entered the field of powder metallurgy material processing with its unique advantages, opening up new prospects for the application of powder metallurgy materials. For instance, using brazing methods commonly employed in powder metallurgy material connections to weld diamonds, due to low bonding strength, wide heat-affected zones, and especially their inability to withstand high temperatures and high strength requirements, brazing material melting and detachment occur. Laser welding can improve welding strength and high-temperature resistance.
Automotive Industry
In the late 1980s, kilowatt-class lasers were successfully applied to industrial production, and today, laser welding production lines have been widely introduced in the automotive industry, becoming one of the significant achievements. European car manufacturers were among the first to adopt laser welding for roof, body, and side frame sheet metal in the 1980s. By the 1990s, the U.S. was rapidly adopting laser welding in automotive manufacturing, although it started later, it developed quickly. Italy has utilized laser welding in most steel plate component assemblies, while Japan has employed laser welding and cutting techniques in manufacturing body panels. High-strength steel laser-welded components are increasingly used in car body manufacturing due to their excellent performance. According to U.S. metal market statistics, by the end of 2002, the consumption of laser-welded steel structures will reach 70,000 tons, tripling from 1998. Given the automotive industry's mass production and high automation, laser welding equipment is evolving towards higher power and multi-channel designs. In terms of technology, the Sandia National Laboratories in the U.S. and Pratt & Whitney have collaborated on research involving the addition of powdered metals and metal wires during laser welding. The Institute of Applied Beam Technology in Bremen, Germany, has conducted extensive research on using laser welding for aluminum alloy body frames, suggesting that adding filler metals in the welds helps eliminate thermal cracks, increase welding speed, resolve tolerance issues, and the developed production lines are already in operation in factories.
Electronics Industry
Laser welding has found extensive applications in the electronics industry, particularly in the microelectronics sector. Due to its small heat-affected zone, rapid and focused heating, and low thermal stress, laser welding demonstrates unique advantages in the encapsulation of integrated circuits and semiconductor devices. It is also utilized in the development of vacuum devices, such as molybdenum focusing electrodes with stainless steel support rings and fast-heating cathode filament assemblies. For elastic thin-walled corrugated sheets in sensors or temperature controllers, with thicknesses ranging from 0.05 to 0.1mm, traditional welding methods are challenging. TIG welding is prone to burn-through, plasma stability is poor, and numerous factors affect the process. Laser welding, however, yields excellent results and is widely applied.
Biomedical
Laser welding of biological tissues began in the 1970s. The successful welding of fallopian tubes and blood vessels, along with the demonstrated advantages, encouraged more researchers to experiment with welding various types of tissues and expand the technique to other applications. Domestic and international research on laser welding of nerves primarily focuses on laser wavelengths, dosage, and their effects on functional recovery, as well as the selection of laser welding materials. Based on fundamental research on small blood vessels and skin by Liu Tongjun, further studies have been conducted on the bile ducts of rats. Compared to traditional sewing methods, laser welding offers advantages such as faster吻合 rates, no foreign body reactions during healing, maintenance of mechanical properties at the welding site, and the repaired tissues grow according to their original biomechanical characteristics, which are expected to lead to wider applications in biomedical fields in the future.
Other Fields
In other industries, laser welding is also increasingly used, especially in China where numerous studies have been conducted on laser welding of special materials, such as BT20 titanium alloy, HEl30 alloy, and Li-ion batteries. Germany has developed a new laser welding technology for flat glass.
