How to save the wire cost in motor production

Some motor manufacturers choose to change aluminum instead of copper wire, but try not to choose long-term cooperation in order to aluminum coil, if a customer needs to use aluminum wire, copper modified method also includes aluminum with a line after saving technology.For motor which is more than 4pole winding embedded is obvious, can save up to 1/6 wire,For example a 5KW electric motor can save 1 to 2KGS wire, it is not related to slot no and size, don't need to change the motor's slot size. 

There are some attention points and defects as changing copper to aluminum, 

 1. Attention points

 a) Wire diameter change is aluminum wire gauge= copper wire gauge*1.28

 b)To keep the resistance,need to improve the filling rate

c)Winding change as tensile strength difference: Aluminum is weaker than copper and easier to break,

   so need to reduce the winding speed when produce the coils

d) The welding and connection method change, Aluminum is easy to be oxygen than copper and hard to welding, Tin for the copper welding is not suitable for aluminum,so some special welding material should be applied

 2. As electrical resistivity of copper and aluminum is much different, improve the wire gauge of aluminum can instead of copper, but connection is a problem 

3. Terminal rivet and copper cover aluminum is the main method in connection. Remove enamelled and welding.Remove enamelled might damage the wire gauge and the surface is black and oxidate to Tin 

4. Regarding riveted connection terminals, aluminum oxide, and soon, in addition to the potential difference between the large copper and aluminum, power generation process will certainly gradually potential corrosion resistance of the connection point will gradually become larger, temperature becomes higher, the last is certainly not energized. Solder wire welding is very problematic, electric iron temperature can not very big, so it is easy to produce sound surfacing false welding, surface looks very full, in fact, which is encased, in addition there is no way a short vaporization flux out Therefore, there will be a lot of solder flux residue charring, this argument is not a reliable way through. Copper clad aluminum wire welding, this approach is self-deception, but on the surface of the copper-tin, aluminum bag inside the tin did not, think you know how serious the problem. . These are process issues. There are material issues. Material is also very critical, like aluminum flux, many of which are currently on the market acidic, more serious corrosion of the aluminum itself, leading aluminum motors, transformers shipped after aluminum corrosion spot into powder.