1. When the radiator and heat pipe are both copper, even brass is fine, which is too little.

2. Both the heat pipe and radiator are made of aluminum.

3. The heat pipe is made of copper and the radiator is made of aluminum.

In the case of 1, 2, 3, generally M5 1 welding wire can be welded with M5 1-F flux, and the welding temperature is 179 degrees, so it can be welded with a hot air gun.

The second welding method can also adopt WE53 low-temperature 400-degree welding, which requires flame welding. The teaching method of welding operation can be searched online for relevant information.