In the production of flat panel solar collectors in the solar thermal industry, whether laser welding technology is stable or ultrasonic metal welding technology has more advantages has always been a hot topic in the industry. The degree of concern is not less than that of vacuum tubes. Solar water heaters and flat-panel solar water heaters. In the process of long-term process technology comparison and the actual application of the product, the two major technical camps of laser welding and ultrasonic metal welding have also formed, and the “contention between Taiwan and Taiwanâ€. This article tries to make a comprehensive comparison between laser welding and ultrasonic metal welding, and analyzes the differences and their respective advantages and disadvantages. First of all, we distinguish the difference between the two welding methods of laser welding and ultrasonic metal welding. Laser welding is the use of heat energy generated by high-energy laser pulses to melt metal materials and create connections. In essence, there is no difference from arc welding except that arc welding is used to generate heat energy instead of laser light. On behalf of manufacturers such as Shenzhen Lianhe laser. Ultrasonic metal welding is the use of high-frequency mechanical vibration of high-density ultrasonic energy generated by the plastic deformation of the workpiece surface and damage the surface layer under pressure, so that the welding of the metal generated at room temperature physical connection. Ultrasonic metal welding does not send current to the workpiece, nor does it introduce high-temperature heat into the workpiece. Only under the combined action of static pressure and elastic vibration energy, the mechanical kinetic energy is converted into the friction energy of the workpiece and the resulting temperature rise occurs. This allows the workpiece to be connected in the solid state. Representative manufacturers such as Foshan Chuxin Electromechanical. It is known through comparison of welding principles that laser welding is achieved by changing the physical structure of the object at a high temperature to achieve the connection of the object, whereas ultrasonic metal welding does not need to change the physical structure of the object to achieve the connection in the solid state. So, which of the two welding technologies is more advantageous and is more suitable for applications in the field of flat panel solar energy? Round 1: Product Aesthetics PK Laser welding is the use of high-energy laser to melt the welded metal to produce a connection, in the solar heat absorbing plate welding in the form of a welding point of 3-5mm welding. Laser welding does not require pressurization on the workpiece to be welded, the overall deformation is small, and the surface damage to the heat-absorbing layer is small, and the ultrasonic metal welding will cause the surface of the sheet to have wavy deformation due to the pressure, although it can be avoided by surface embossing. Deformation, but will still form a 3mm weld mark on the surface of the solar heat absorption. Therefore, the appearance of products using laser welding will be superior to ultrasonic metal welding. This round of competition, laser welding is better than ultrasonic metal welding. Round 2: Effect Persistence PK Laser welding solder joint strength is poor, hot and cold alternately or subject to external force, the solder joint is easy to break. In ultrasonic metal welding, the two objects to be welded are overlapped by vertical pressurization and combined by ultrasonic vibration and pressure to form a solid state connection. The bonding time is short and the combined part does not generate cast microstructure defects. Therefore, the welding position is uniform and the stability is strong, and the ultrasonic metal is used. After the welding has passed the ninety-degree vertical bending test, no fracture phenomenon still occurs. This round of competition, ultrasonic metal welding is better than laser welding. Round 3: Thermal Conductivity PK The use of laser welding will change the physical structure of the welded object, thus affecting its conductive or thermal conductivity, and laser welding results in a small absolute thermal conduction area between the solar collector's metal sheet and the copper tube, which affects the heat transfer efficiency. Ultrasonic metal welding does not have this problem. Ultrasonic welding can minimize the temperature effect of the material, so that the metal structure does not change, so the electrical conductivity or thermal conductivity after welding is very good, the resistance coefficient is very low or nearly zero, ultrasonic metal welding has become conductive, thermal conductive material welding The best choice, this performance in the application of flat-panel solar collectors can obviously produce laser welding can not achieve the advantages. Tested ultrasonic metal welding products than the laser welding conduction efficiency is about 3% higher (that is, under the same conditions, the water temperature is high about 3%). This round of competition, ultrasonic metal welding is obviously better than laser welding. Round 4: Energy Consumption PK As a representative product of low-carbon energy-saving and environmental protection, solar water heaters have been widely recognized by the society and consumers. The energy consumption indicators in the production process are also receiving much attention. The welding of solar collectors is one of them. From the comparative analysis of the welding principle, it can be known that the ultrasonic metal welding can minimize the temperature effect of the material (the temperature of the weld zone does not exceed 50% of the absolute melting temperature of the welded metal) so as not to change the metal structure, so it does not Annealing metal workpieces, also do not need cooling water, energy consumption, the same kind of metal and different metals can be ultrasonic welding, compared with laser welding consume much less energy. This round of competition, ultrasonic metal welding is better than laser welding. Round 5: Cost PK First, equipment costs: internationally speaking, the price of ultrasonic welding machine and laser welding machine is similar, but Chuxin Electromechanical Co., Ltd. has introduced the first automatic full-plate ultrasonic metal welding machine for solar energy thermal utilization industry through the introduction of technology from abroad and independent research and development. Completely broke the ultrasonic welding equipment in China needs to rely on the status of foreign imports, so that the price of domestic ultrasonic welding machine is basically reduced by half. Ultrasonic metal welding machine single equipment procurement costs lower than the laser welding machine, the procurement ratio of the two is usually 300,000: 1 million (now the price of domestic laser welding machine is also rapidly falling, about to drop to about 700,000). The laser welding machine generally has two laser welding heads, and the ultrasonic machine generally has one welding head. For the same production capacity, two ultrasonic welding machines are compared with one laser welding machine, and the ultrasonic wave is slightly better than the laser. The second is the use of cost: First of all laser welding to adapt to thick materials, such as welding aluminum, aluminum plate thickness is generally selected as 0.4mm, and ultrasonic welding to adapt to thin products, such as aluminum, generally choose 0.2-0.3mm. Ultrasonic waves are superior to welding materials. Followed by the cost of consumables, laser welding consumables are xenon lamps and filter cartridges, etc. Ultrasonic consumables are welding heads. In general, laser welding supplies are cheaper than ultrasound. Therefore, this round of competition, ultrasonic metal welding is slightly better than laser welding. Round 6: Efficiency PK Ultrasonic metal welding speed is faster than laser welding: Typical ultrasonic metal welding speed is 8m/min for welding copper and 12m/min for aluminum, but the current ultrasonic welding process is selected by first rolling and then welding, so the efficiency of a single machine is To fight in half. For the same production capacity, two sets of ultrasonic welders are compared with one sets of laser welders. In this comparison, ultrasonics are superior to lasers. After several negative comparisons, we found that ultrasonic metal welding is superior to laser welding in the solar industry. Moreover, from the experience of using ultrasonic metal welding as the main welding technology in the field of solar energy in our country, there has been a wealth of application experience, which is why the solar energy companies that have launched many flat projects in the past two years also chose ultrasonic metal welding. As for the high cost of welding equipment previously considered by many solar energy companies, it has also been greatly eased with the listing of the fully automatic ultrasonic welding machine for metal plates independently developed by Chuxin Electromechanical. Which kind of welding technology has more advantages, the choice of the market will become the most effective way to verify, the author also looks forward to the further leap of China's metal welding technology as the majority of readers, so that many production-oriented enterprises and the vast number of consumers can experience and enjoy technology The fruits of progress. Author: Liu Xu Ningbo Wason Lighting Technology Co.,Ltd , https://www.wasonlight.com