Comparison Of Advantages And Disadvantages Of Several Welding Methods

Compared to other welding technologies, the main advantages of laser welding are:

1. Fast speed, large depth, and small deformation.
2. Welding can be carried out at room temperature or under special conditions, and the welding equipment is simple. For example, when a laser passes through an electromagnetic field, the beam does not shift; Laser can perform welding in vacuum, air, and certain gas environments, and can be welded through glass or materials that are transparent to the beam of light.
3. It can weld refractory materials such as titanium and quartz and can weld dissimilar materials with good results.
4. After laser focusing, the power density is high. When welding high-power devices, the aspect ratio can reach 5:1, with a maximum of 10:1.
5. Can be used for microwelding. After focusing the laser beam, a very small spot can be obtained and accurately positioned, which can be applied to the assembly welding of micro and small workpieces in large-scale automated production.
6. It can weld difficult-to-access parts and has great flexibility by implementing non-contact long-distance welding. Especially in recent years, fiber optic transmission technology has been adopted in YAG laser processing technology, making laser welding technology more widely promoted and applied.
7. Laser beams are easy to achieve beam splitting in time and space, allowing for simultaneous processing of multiple beams and multiple workstations, providing conditions for more precise welding;

Resistance welding has the following advantages:

1. When the molten core is formed, it is always surrounded by a plastic ring, isolating the molten metal from the air, and the metallurgical process is simple.
2. Short heating time, concentrated heat, small heat affected zone, small deformation, and stress, usually without the need for calibration and heat treatment procedures after welding.
3. No need for filler metals such as welding wires and rods, as well as welding materials such as oxygen, acetylene, and argon, resulting in low welding costs.
4. Easy to operate, easy to achieve mechanization and automation, improving labor conditions.
5. High productivity, without noise or harmful gases, can be combined with other manufacturing processes in mass production to assemble on the assembly line. But flash butt welding requires isolation due to spark splashing.

Disadvantages of resistance welding:

1. At present, there is a lack of reliable non-destructive testing methods and welding quality can only be checked through destructive testing of process samples and workpieces, as well as various monitoring technologies to ensure.
2. The lap joint of point and seam welding not only increases the weight of the component but also has lower tensile and fatigue strength due to the formation of an angle around the fusion nucleus between the two plates.
3. The equipment has high power and a high degree of mechanization and automation, making it costly and difficult to maintain. Additionally, the commonly used high-power single-phase AC welding machines are not conducive to the normal operation of the power grid. With the development of industries such as aerospace, electronics, automobiles, and household appliances, wear-resistant welding rods have attracted increasing attention from society. At the same time, higher requirements have been put forward for the quality of resistance welding. Fortunately, the development of microelectronics technology and the development of high-power thyristors and rectifiers in China have provided conditions for the improvement of resistance welding technology. At present, China has produced high-performance secondary rectifier welding machines. The control box made of integrated components and microcomputers has been used for the matching of new welding machines and the renovation of old welding machines. Advanced closed-loop monitoring technologies such as constant current, dynamic resistance, and thermal expansion have begun to be promoted and applied in production. All of this will be beneficial for improving the quality of resistance welding and expanding its application fields.