Laser head welding promotes the development of new energy vehicles

Laser head welding promotes the development of new energy vehicles

At present, many countries have promulgated laws and regulations on the elimination of petroleum fuel vehicles in the future, that is, new energy vehicles will gradually replace fuel vehicles in the next few decades. This means that electric vehicles and their power batteries will gradually become a huge market. At present, the absolute main force on the road is still the fuel car. Eliminating fuel vehicles in a short period of time is not realistic. However, at least one thing is certain - the continued development of electric vehicles is an unstoppable trend. European countries have also set time limits for the sale of fuel vehicles. In this regard, more aggressive countries like Norway have made 2025 the year to stop selling fuel cars and 2040 the year of more moderate UK laws. According to the situation in China, the phase-out of petroleum-fueled vehicles should be 10 to 20 years later than in Europe. However, there is no doubt that new energy vehicles represented by electric vehicles will undoubtedly become the major players in the future.

With the increase in demand for new energy vehicles, the demand for light new energy vehicles and power batteries will naturally rise, and the laser welding application market will also become hot. With the development of new battery technologies and higher capacities, the demand for connectivity technology continues to increase. The electric vehicle industry in particular is driving this trend. The automotive industry and its suppliers are looking for a robust and efficient welding process to produce the high volume copper and aluminum joints widely required in power batteries, power batteries and electric vehicle storage products.

In recent years, fiber laser welding has made great technological progress, which is beneficial to vehicle lightweighting and battery manufacturing. Fiber laser welding continues to expand its range of materials and applications. Innovations in laser technology and beam delivery components overcome the challenging applications of traditional laser welding, such as welding copper, dissimilar materials, thin metal foils or poorly assembled parts. Fiber lasers have an increasing number of beam properties, wavelengths, laser powers and pulse durations. Fiber lasers have shown promise through advanced wobble welding techniques to alleviate these problems through improved coupling with highly reflective materials, improved solidification behavior of the weld pool, elimination of defects, improved penetration depth control, and component assembly with poor compensation. Fiber laser welding technology has contributed to low-cost and high-reliability batteries for the latest generation of electric vehicles. Fiber laser welding reliably provides consistent, high-quality welds for electric vehicle batteries, welding aluminum, copper, nickel-plated steel, and combinations of these materials.

The fiber laser head has the best beam quality, the highest brightness, the highest output power and the highest electro-optical conversion efficiency. These factors make fiber lasers much better than other lasers in terms of processing efficiency and cost. Traditional laser welding techniques, such as continuous wave CO2 welding lasers, are limited in terms of accuracy and high heat input, which can be expected to be avoided during welding. On the other hand, the limitations of conventional pulsed Nd:YAG are the maximum welding speed, the minimum achievable spot size and the available electro-optic energy conversion efficiency. Compared with the traditional CO2, YAG and other laser welding processes, the fiber laser welding process has obvious advantages. This is mainly due to the low reflection coefficient of metal materials for the excitation light of 1070nm fiber. The advantages of high-power fiber lasers are especially evident when welding metallic materials with high reflectance, such as aluminum and copper. More and more applications require higher precision control, lower heat input and lower power consumption. Continuous wave fiber laser welding is one technology that provides these capabilities. As a result, fiber laser welding is becoming more and more popular in the automotive industry and the industries represented by its suppliers.

Currently, foreign companies developing fiber laser systems for battery welding include IPG in the US and Tongkuai in Germany. As a fiber laser welding agent, the domestic company is a joint venture laser, and its products include 1-4kW fiber welding machines. Allied Laser believes that the prospect of power batteries is very good, and the growth of laser welding performance is very optimistic. In 2017, the company achieved a total operating income of 728 million yuan, a year-on-year increase of 74.86%. It is predicted that the domestic demand for power batteries will reach 146GWh in 2020, 3.7 times higher than that in 2016. At that time, the rapid development of new energy vehicles will bring strong demand for laser welding power batteries.

In 2017, the market size of China's laser welding processing equipment exceeded 6 billion yuan, an increase of 35% over the previous year, showing a trend of accelerated growth. Currently, there are several types of laser processing. Finishing includes marking, repairing, reinforcing, cutting and welding. Compared with the 25 billion cutting market, the welding scale is still not up to the standard. The specific reason is that the laser welding process is more complex, and there are more custom processing cases. For penetration welding, deep penetration welding, custom welding or lap welding, the same or different materials must be considered. Second, it is necessary to consider which laser and power to use depending on the material. Finally, it is necessary to provide a high-performance laser welding solution with a highly automated operating system, precise positioning fixtures, machine vision, and more. Also, cost should be considered compared to arc welding and spot welding. These are all important reasons why the laser welding market has not done much in the past. However, the development of customized laser welding solutions has become more and more mature in the past two years, only when the hot spot of market application broke out.

In the past three years, the state has vigorously supported the development of new energy electric vehicles and promoted the development of power battery laser processing equipment. In 2017, it will bring at least 2 billion laser equipment requirements for laser welding. In the future, laser welding of consumer electronic components, including welding, metal plates of electronic products and metal casings of electronic products, may trigger the laser welding market again. In the future, polymers, especially plastics, may have good welding potential. Plastic is a metal, wood and cloth widely used in daily life, including furniture, household appliances, toys, communication equipment, glasses, kitchenware and other hundreds of industries. However, laser processing of plastics has always been a difficult problem due to the thermal melting effect of lasers, and the market is unlikely to expand. What remains untapped is the one with the greatest market potential.

Fiber lasers are known to require relatively high power to weld metal, and high output power means that the laser and laser welding tip will remain hot. In order to prevent the laser and welding head from getting too hot, a chiller is necessary and very high temperature control is required.

Before 2014, there were about 10 large domestic companies engaged in laser chillers, but now there may be more than 30, which is also the result of the development with the increase in the number of laser equipment companies. Guangzhou Teyu Electromechanical Co., Ltd. is the largest and most powerful electromechanical company in South China. Its goal is the rapid development of domestic fiber laser welding. Teyo introduced a refrigeration system with dual cycle and dual temperature coolers. It adopts two independent dual temperature control designs and supports Modbus communication protocol. It can realize the communication between the laser system and the chiller, monitor the working status of the chiller, and modify the parameters of the chiller. When the working environment and the requirements of the chiller change, the user can modify the parameters of the chiller through the control program to suit the working environment and requirements.