Discussion on the connection technology of copper and aluminum terminals of electric vehicle high voltage wire harness

With the rapid development of electric vehicles, high-voltage wiring harness is an important part of electric vehicles, and the reliability and stability of its connection technology is very important. As a common connection mode, copper-aluminum terminal connection has been widely used in high voltage wiring harnesses of electric vehicles. However, there are a series of problems in the welding of copper and aluminum, this paper will analyze the copper and aluminum terminal connection technology, and explore its solution.

1. Problems faced by copper-aluminum welding

1.1 Thermal expansion coefficient and thermal conductivity are different

The thermal expansion coefficient and thermal conductivity of copper and aluminum are different, and the heat condition during welding will lead to the difference of the expansion amount of copper and aluminum materials, which may cause the deformation and crack of the welded joint.

1.2 Dissimilar metal composite welding is brittle

Copper-aluminum welding is easy to form a brittle phase, such as copper aluminide, which forms a brittle compound at the weld, affecting the strength and stability of the welded joint.

1.3 Welding problems caused by melting point difference

The melting point of copper and aluminum is very different, and the aluminum is easily melted but the copper is not welded through, so it is necessary to debug the appropriate process parameters.

2. Solution and technology application

2.1 Control welding temperature and time

In the welding process, it is necessary to control the heat condition and welding time of the welding surface to avoid the increase of thermal expansion difference caused by too long welding time, thus affecting the welding quality.

2.2 Optimization of welding process parameters

Aiming at the problem of high brittleness in the welding of copper and aluminum dissimilar metal composite, the welding process parameters can be optimized, the appropriate welding materials and welding process can be selected, and the formation of brittle phase can be reduced.

2.3 Process debugging and control

In view of the welding problems caused by the difference of melting points of copper and aluminum, it is necessary to conduct process debugging and control to ensure that copper and aluminum can reach the welding temperature at the same time to ensure the integrity and quality of welding.

3. Technical application case analysis

In order to more specifically understand the application of copper-aluminum terminal connection technology in electric vehicle high-voltage wiring harnesses, the following will introduce a practical technical application case.

3.1 Case Description

In the production process of an electric vehicle manufacturer, it is faced with the challenge of applying copper-aluminum terminal connection technology. In the manufacturing process of high voltage wiring harness of electric vehicles, the welding quality of copper and aluminum joints is prone to problems such as unstable welding quality and large contact resistance, which seriously affect the reliability and stability of the wiring harness.

3.2 Solution Selection

In response to the problems faced by copper-aluminum terminal connection technology, the manufacturer has adopted the following solutions:

Process parameter optimization: Optimize and adjust the welding process parameters, including welding temperature, welding pressure, welding time, etc., to ensure that copper and aluminum can reach the welding temperature at the same time, improve welding quality and stability.

Welding material selection: Select the welding material suitable for copper and aluminum connection, and reduce the risk of brittle phase generation in the welding process through reasonable welding material ratio and additives, and improve the strength and stability of the connection.

Process control and inspection: Strict process control and quality inspection mechanism is introduced to monitor and record the entire welding process to ensure that the welding quality is up to standard and the welding joints meet the design requirements.

3.3 Implementation effect evaluation

Through the implementation of the above solutions, the electric vehicle manufacturer has successfully solved various problems in the application of copper-aluminum terminal connection technology. In actual production, the welding quality is stable and reliable, the contact resistance is significantly reduced, and the reliability and stability of the wire harness are significantly improved.

Copper and aluminum terminal connection technology has important application value in electric vehicle high voltage wiring harness, by exploring and solving the problems faced by copper and aluminum welding, it can further improve the connection quality and stability, and promote the development and application of electric vehicle technology. In the future, with the continuous innovation and improvement of technology, copper and aluminum terminal connection technology will be further optimized and improved, and make greater contributions to the development of the electric vehicle industry.