TIG Welding Quality Inspection for Aluminum Radiators: Weld Defects and Leak Testing

TIG (Tungsten Inert Gas) welding is used for aluminum radiator components where joint integrity and sealing performance are essential. Defects such as cracks, porosity and incomplete fusion can compromise weld quality and cause leakage.

A reliable inspection process combines visual examination, leak testing and, when required, internal defect inspection and mechanical testing.

Visual inspection helps identify surface defects and assess weld appearance. Based on the supplied technical criteria, the main acceptance points include:

• Weld appearance: The bead should be uniform and continuous, with a smooth transition to the base material. Weld leg dimensions must follow the drawing, with a tolerance of ±0.5 mm.

• Weld reinforcement: 0–1.5 mm, with no concavity below the base material.

• Undercut: Depth ≤0.3 mm, individual length ≤5 mm, and total length ≤10% of the weld length.

• Surface porosity: Total pore area ≤1% of the weld area for Level C and ≤0.5% for Level B. Chain-like and elongated tubular pores are not permitted.

• Prohibited defects: Cracks, crater cracks, incomplete fusion, through-thickness pores, excessive weld metal and extensive slag inclusions.

• Surface cleanliness: Spatter and aluminum residue must be removed from the weld and surrounding sealing surfaces.

GB/T 22087 and ISO 10042 address quality levels for imperfections in aluminum and aluminum-alloy arc-welded joints. The applicable quality level and product-specific acceptance requirements should be defined in the inspection documentation.

A visually acceptable weld may still contain a leakage path. Leak testing is therefore essential for verifying the sealing performance of aluminum radiator components.

Common methods include:

• Water or pressure testing: Apply the specified test pressure and holding time. No bubbles or leakage are permitted under the stated acceptance procedure.

• Helium leak testing: When required, confirm that the measured leak rate does not exceed the specified limit.

• Repair and reinspection: The supplied criteria limit repairs at the same location to no more than two attempts. After repair, repeat all applicable inspections and tests.

Test pressure, holding time and allowable leak rate must follow the product drawing and approved test procedure.

When required by the inspection plan or customer, radiographic testing and other suitable methods can help identify internal weld imperfections.

For welding procedure qualification, the supplied criteria specify joint tensile strength ≥85% of the base material's minimum strength, no cracking during bend testing, and no obvious overheating or excessive grain growth in the heat-affected zone.

Consistent weld quality depends on material preparation, joint fit-up, welding parameters and effective inspection. Combining visual examination with appropriate leak testing helps manufacturers identify defects, reduce rework and improve product reliability.

SUNHOPE supplies radiator manufacturing equipment, components and technical support, including radiator core assembly machines, fin forming machines, aluminum brazing furnaces and leak testing equipment. These solutions support manufacturers establishing new production facilities or upgrading existing production lines.

1. How do you inspect TIG welds on aluminum radiators?

Visual examination identifies surface imperfections, while leak testing verifies sealing performance. Additional tests may be required by the inspection plan.

2. Can visual inspection detect every radiator weld leak?

No. Some internal defects and leakage paths are not visible, making suitable leak testing essential.

3. What determines acceptable weld porosity?

Acceptance depends on the specified quality level and applicable inspection criteria. The supplied surface porosity limits are ≤0.5% for Level B and ≤1% for Level C.

4. Is ISO 10042 a radiator leak-testing standard?

No. ISO 10042 classifies imperfections in aluminum and aluminum-alloy arc-welded joints. Leak-test methods and allowable leak rates must be specified separately.

5. What equipment is used for radiator leak testing?

Depending on the product and required sensitivity, manufacturers may use pressure-based leak testers or helium leak-testing systems.

Technical note: Apply the relevant edition of GB/T 22087 or ISO 10042, together with product drawings and approved inspection procedures, when establishing weld acceptance criteria.