Effect of Zinc plating on Mag Properties of 1008 Steel

[cesaredu13]

Good day to all,

i am new on this forum, and i am really excited on learning more on magnetic poperties of materials.

I have a doubt regarding an armature-yoke system we are using, the system is very simple (see attached picture)
is a steel 1008 yoke with a current carrying cable in the midle to create the magnetic fiel and attract the armature towards the yoke when a current is applied, the dimensions of the yoke is .250 in W x .150 in H X .750 in D, we use this part with Zinc plating , the plating spec thickness is around .00032 in.

My question is if it could be an effect on the magnetic response of the 1008 steel because of the plating, will different plating thickness affect the total induced flux intensity (B) affecting with this the current necesary to attract the armature towards the yoke.

I have a current spec at wich the armature shoul be attracted to the yoke, and i am looking for variables that could affect this current, i already know that the gap between the armature and yoke is very critical, but looking for some other variables.

Thanks in advanced for your help....this is a great forum.

 

[israelkk]

The zinc plating is exactly as air from magnetic point of view for a DC solenoid. However, for an AC excitation the eddy currents will flow in the zinc too. If the force is needed when the yoke is touching the armature then the zinc plating thickness will serve as an air gap and its value will affect the holding force. If the force is needed when the armature is far from the yoke the plating thickness affect is negligible.

 

[cesaredu13]

Thanks you israelk, now i see it more clearly.