GB/T 41104.3-2021 in English

Technical background of the standard

As the third part of the GB/T41104 standard, this document establishes a quantitative detection system for the wetting performance of flux-cored solder wire. The wetting balance method objectively evaluates the activity of the flux and the welding performance of the material by measuring the force changes of the copper specimen in the molten solder.

Core test principle

Based on the Archimedean principle, when the SAR copper specimen and the flux-cored solder wire are simultaneously immersed in the molten alloy, the system records the dynamic curve of the combined effect of buoyancy and surface tension. By calculating parameters such as the wetting angle θ and the wetting velocity, the flux efficacy is quantitatively characterized.

Instrument system requirements

Key points of test operation

1. Sample preparation: Take a 20cm long solder wire and clean the surface with acetone
2. Parameter setting: Immersion depth 3±0.2mm, holding time 10±1s
3. Data acquisition: Repeat the test for at least 10 times to take the average value
4. Scum treatment: Use a heat-resistant scraper to clean the molten surface before each test

Standard technology evolution

Compared with ISO122243:2003, this standard has the following major improvements:

• Add Appendix B to specify the technical requirements for instruments
• Adjust the reference standard system (such as replacing the IEC standard with GB/T2423.32)
• Refine the requirements for the sulfurization process of copper specimens

Implementation recommendations

To ensure test accuracy, it is recommended to:

• Regularly calibrate the force sensor and temperature control system
• Copper specimens should be stored in an anti-oxidation manner
• The depth of the solder bath should be maintained constant (±1mm from the edge of the crucible)
• Abnormal data needs to be analyzed for the impact of ambient temperature and humidity