Free sample
Applicable material: 1060 3003 5052 5083 6061, etc. (aluminum profiles can be used)
Product application: new energy auto parts, car water tank, solar heat dissipation plate, water cooling plate, lighting lighting, solar reflector, architectural appearance, ceiling, furniture, cabinets, elevator, luggage, car interior and exterior decoration, refrigerator, microwave oven, etc
With the promotion of green concept in the new era of reform, the development concept of green environmental protection has gradually infiltrated into the field of automobile manufacturing. The research and development and launch of new energy vehicles can solve the environmental pollution brought by traditional fuel cars and effectively alleviate the problem of global energy shortage and waste. This paper focuses on the analysis of the welding technology used by new energy vehicles, combing the application of aluminum spot welding in the new energy all-aluminum vehicle body, hoping that the study of this paper can provide theoretical support for the review and manufacturing of new energy body in the future.
Key words: new energy vehicles; Intelligent manufacturing; Welding technology; Whole aluminum body
With the continuous improvement of human production and living standards, the problem of environmental pollution is becoming more and more serious, and people are more and more interested in new energy vehicles. Made in China 2025 and the implementation of the strategy of our country industry 4.0, new energy automotive industry received strong support, new energy vehicles for the battery energy density and other technical requirements and restrictions, automotive equipment quality than traditional energy vehicles put forward higher requirements, adopt aluminum alloy material, can effectively reduce the weight of the body, In line with the development trend of new energy vehicles. The traditional resistance welding method has low cost and stable quality, and is widely used in the production field of traditional energy vehicles. Generally speaking, resistance spot welding is often used to complete the welding of steel body. The body of new energy vehicles mostly uses ultra-high strength steel, aluminum alloy and other composite materials, and also introduces bonding technologies such as adhesive and laser welding. The welding quality of new energy all-aluminum body is directly related to the quality of vehicles. If the occurrence of virtual welding or over-welding in the welding process will directly affect the safety of vehicles and the promotion of new energy vehicles. Therefore, higher requirements are put forward for the welding quality of new energy all-aluminum body. This paper mainly studies the application of spot welding technology in the welding process of all-aluminum body.
Welding performance of aluminum alloy
Generally speaking, aluminum alloy welding needs to consider the base metal, welding process and welding process of three aspects. According to the difference of aluminum alloy forming way, it can be divided into deformation aluminum alloy and cast aluminum alloy. Different aluminum alloy material front-degree mechanism directly affects the formation of microstructure and welding defects in the body spot welding process. Aluminum alloy commonly used heat treatment process includes: annealing state: mainly in order to eliminate the effect of aluminum alloy work hardening and internal stress. Solution treatment and natural aging: the soluble phase is dissolved by heating, and then cooled rapidly to improve the strength, hardness and corrosion resistance of aluminum alloy. Solution treatment and unsafe artificial aging: obtain high strength and high plasticity materials, such materials have low corrosion resistance. Solution treatment and complete artificial aging: product strength is higher, but will reduce corrosion resistance and plasticity. Solution treatment and stabilization tempering: stabilize the structure and size of casting to ensure high mechanical properties.
Spot welding of aluminum body
Common welding process design mainly includes plate lap form and process size; The welding process involves welding method, welding equipment, pre-welding/post-welding treatment and process parameters, etc. To complete spot welding of all-aluminum body, it is necessary to fully consider the particularity of aluminum alloy material and the new requirements of new energy vehicles for welding foundation. The heat dissipation of aluminum alloy material is very fast, and it has high conductivity. In the process of welding, the part in contact between welding parts and electrodes is prone to overheating, which leads to the bonding of welding parts and electrodes, increasing the difficulty of welding. Before deciding on the welding scheme, it is necessary to ensure that high quality molten core can be formed in a short time. In the process of spot welding, the current density should be greater than 100A/mm², which is 2 to 3 times of ordinary low carbon steel. The choice of welding machine should choose high-power equipment. In the process of spot welding of all-aluminum body, there are the following key points: first, attention should be paid to the state and cleanliness of the surface of aluminum alloy. Before spot welding, the surface must be cleaned to remove magnesium oxide and chromium on the surface. During spot welding, the cooling strength of electrode should be strengthened to ensure the uniform contact between electrode and workpiece; Secondly, the quality of spot welding joints must be selected in the process of spot welding; The third is to pay attention to the quality of spot welding joints, can use the traditional damage detection and point-line ultrasonic testing method combined detection scheme.
Main research results of resistance spot welding of aluminum alloy automobile body
(1) Medium frequency DC welder. The outstanding advantage of using this spot welding machine is that the energy it provides can be flexibly switched between plates of different thickness. In the process of aluminum spot welding, the current transmission efficiency and utilization rate can be improved. (2) AC welder. The use of AC welder can balance electrode wear, improve the dc welder positive and negative electrode wear imbalance problem, effectively prolong the service life of the electrode, while avoiding the deviation of welding core. (3) The shape of electrode cap changes. The multi-ring electrode cap technology of General Motors can effectively achieve the separation and crushing of oxide film, making the welding process more smooth. (4) ARO Welding clamp equipment in France developed a set of aluminum welding clamp using electronic servo and pressure feedback to achieve variable pressure welding, using this equipment can reduce welding cracks caused by improper welding pressure and other problems. (5) (Jiangmen Chengrui Technology) developed a special aluminum welding wire for new energy vehicles, which fully takes into account the particularity of aluminum alloy materials and the new requirements of new energy vehicles for welding foundation. Spot welding technology research and improvement for all-aluminum body is still the focus of research and focus on improving welding quality.
4 conclusion
In the next few years, the research and improvement of spot welding technology of all-aluminum body is still the focus and focus of research. The core is to improve the strength of spot welding of aluminum alloy materials and ensure the stability of quality. It is believed that with the industrial development of aluminum spot welding, it will be able to further reduce the production and manufacturing cost of new energy vehicles.
