Hiperco 50 after laser cutting of laminations 2

[Clyde38]

I have recently been told that Hiperco 50 loses a significant portion of it's desired magnetic properties after laser cutting for stators. Is this true? I have not heard this before.

Clyde Hancock
Design & analysis of electric motors and generators

http://www.motorconsultants.com

 

[EdStainless]

How are you removing the re-cast from the edges?
How are you assuring that the lams stay insulated from each other?

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P.E. Metallurgy, Plymouth Tube

 

[Clyde38]

One of my customers presented this issue to me so I'm not sure how the lamination material is processed after laser cutting. They are individually cut with the laser and then stacked with Backlack (adnesive) and this constitutes the inter-lamination insulation. One possible supplier is Polaris Laser Laminations, LLC (

http://www.polarislaserlaminations.com/bonding.html).

Clyde Hancock
Design & analysis of electric motors and generators

http://www.motorconsultants.com

 

[EdStainless]

When you laser cut it leaves a layer of melted and resolidified material.
This can have very different properties than the wrought material.
It can also leave a ridge of material along the cut edge.
Unless these are very small I don't see how laser cutting them can have a significant impact.

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P.E. Metallurgy, Plymouth Tube

 

[MagBen]

I have ever read a report saying laser cutting/EDM decreased saturation by up to 10%, which led to drastically increased hysteresis loss (EDM was worse due to Cu pollution). I personally do not believe laser cutting had such a high impact on magnetic performance, unless the heat effect zone was significant compared with the whole tested ring, which in practical is not the case.

 

[Clyde38]

Thanks for the feedback. This particular customer has a stator OD of 23 mm for an outside rotor BLDC motor. Is there a process after laser cutting to address this if it is an issue?

Clyde Hancock
Design & analysis of electric motors and generators

http://www.motorconsultants.com

 

[MagBen]

I bet you do a final anneal after cutting, right? if not, recommend doing so. Another way is to stamp the lam to do a comparison with laser cutting if you do have concern on laser.