How to ensure the firmness of the welding between the aluminum seat and the aluminum frame of the universal wheel aluminum box?

Before welding, the contact surface of the aluminum seat and the aluminum frame of the universal wheel aluminum box must undergo strict surface treatment, including mechanical grinding to remove the oxide layer, and using solvents such as acetone to clean oil and impurities. The choice of welding process directly affects the strength and durability of the weld. For high-precision welding needs, TIG welding is usually used because its heat input is controllable, which can reduce the deformation of aluminum materials, and argon protection is used to prevent weld oxidation. For mass production with high production efficiency requirements, MIG welding is more suitable, but the welding parameters need to be strictly controlled to avoid burning through or deformation of the aluminum plate due to excessive heat input.

The settings of welding current, voltage and speed must be adjusted according to the thickness of the aluminum material. For example, a 3mm thick aluminum plate is usually welded with a current of 80~120A. The selection of welding wire is also critical. It is recommended to use welding wires such as ER4043 or ER5356 that match the parent material to ensure the mechanical properties of the weld. In addition, the welding process needs to maintain a uniform speed to avoid local overheating, thereby reducing the occurrence of defects such as pores and cracks.

Continuous fillet welds are usually used for the edges of the aluminum seat and the aluminum frame, rather than spot welding, to ensure that the welded parts can be evenly stressed. The size of the weld leg needs to be designed according to the load-bearing requirements of the box, and its strength is verified by mechanical calculation. Reasonable weld design can effectively disperse stress and avoid fatigue cracking of the welded parts during long-term use.

After welding is completed, strict quality inspection is required. Visual inspection is the most basic step to confirm whether the weld has defects such as cracks, undercuts or lack of fusion. For more demanding applications, penetration testing can be used to detect surface microcracks, or X-ray and ultrasonic testing can be used to check potential defects inside the weld.

In order to verify the strength of the welded parts, sampling tensile tests are usually performed to ensure that the tensile strength of the weld is at least 70% of the strength of the parent material. In addition, impact testing can simulate the use of the box in a bumpy environment and evaluate the fatigue resistance of the welded parts.

In key stress-bearing parts, such as around the aluminum seat, triangular reinforcement sheets can be added and fixed to the aluminum frame by welding to further disperse the stress. For boxes with high load requirements, the welded parts can also be repaired to improve local strength.

After welding, the weld area usually needs to be polished to reduce stress concentration points. In order to improve corrosion resistance, the welded parts can be anodized to form a dense oxide film. In addition, applying weather-resistant sealant around the weld can effectively prevent the intrusion of moisture and corrosive media, thereby extending the service life of the welded parts.