Introduction
In this paper, we will discuss the development status of pulse pressure welding technology. Pulse pressure welding technology is an advanced welding technology in the welding industry. It has the advantages of fast welding speed, good penetration depth and less deformation of parts. The existing development of pulse pressure welding technology mainly includes two aspects: welding structure and process. This paper will analyse and discuss the development status of pulse pressure welding technology from these two aspects.
Welding structure
At present, the welding structure of pulse pressure welding technology mainly includes two structures: single pulse pressure welding and multi-pulse pressure welding.
Single pulse pressure welding is the most basic and simplest welding structure. This structure is composed of relatively simple components and its structure is relatively simple. The welding time of single pulse pressure welding is very short, and the effect of welding can be obtained in a few milliseconds. Pulse pressure welding of surface mount technology (SMT) largely belongs to single pulse pressure welding structure, in the surface mount technology applications, the workpiece position is fixed, which greatly simplifies the welding structure of pulse pressure system.
Multi-pulse pressure welding structure is more complicated than single pulse pressure welding structure. This structure consists of several modules of pressure forming, pulsed supply and pressure control. It has higher requirements for welding precision and welding consistency. The welding time of multiple pulse pressure welding is also very short, which can be completed in hundreds of milliseconds of overlapping welding process. Multi-pulse pressure welding is mainly used in engine manufacturing, aerospace industry and other high-precision components, to achieve higher welding quality and welding precision requirements.
Process
Pulse pressure machining process is mainly for high-speed and high-precision multi-pulse pressure welding technology, its main process characteristics are short welding time and high welding efficiency. The welding process of pulse pressure welding includes several steps: forming, preloading, current, welding and unloading.
Forming: In this step, the weld joint is formed in advance. When the welding joints of some workpiece are relatively simple, the prior forming of joint surface can be omitted, and the weld joint surface is dynamic during welding process.
Preload: In this step, the weld surface is preloaded to a certain value, so that the weld joint surface is in close contact and there are no surface gaps.
Current: During this period, high current can be instantly applied, and electricity is used to form arc and generate heat.
Welding: This is the key process of pulse pressure welding, and it needs to use short pulse current instead of direct current. The short, large-void pulse current can reduce the welding resistance and form arc, which has higher current carrying capacity than direct current.
Unloading: In this step, the preload is relieved, and welding process is finished.
Discussion
In the past few years, pulse pressure welding technology has developed rapidly. Traditional pulse pressure welding technology has been used in many practical projects and has achieved good results. The advantages of pulse pressure welding technology are obvious, it has high welding speed, high production efficiency and good welding quality. At the same time, the arc stability and pressure stability during welding process are also very good, which can ensure the stability of welding quality.
At present, pulse pressure welding technology is not only used in surface mount technology field, but also widely used in automobile, aircraft, missiles and other industries. In automobile industry, pulse pressure welding technology is mainly used for high strength and high-precision steel parts welding. In aircraft manufacturing, pulse pressure welding technology is used to weld the structure parts of aircraft, which has higher requirements for welding quality and welding speed. In addition, pulse pressure welding technology has been widely used in other fields, such as household electronics, medical equipment, communications equipment, etc.
Conclusion
In conclusion, pulse pressure welding technology has been widely used in a variety of industries in recent years. Its advantages are obvious, such as fast welding speed, good penetration depth and less deformation of parts. The welding structures includes single pulse pressure welding and multi-pulse pressure welding. The welding process includes forming, preloading, current, welding and unloading.In the future, the development of pulse pressure welding technology will be faster, and its application range will be more widely.
