Corrosion protection for aluminum die casting

[grayseal]

A heating element is incorprated into the wall of a small (3" diameter by 2" high) die cast aluminum (A360) boiler used to generate steam for sterilization. Current castings have been Keronite coated. After a few cycles, white debris is found throughout the system. EDS analysis confirms that it is mostly aluminum oxide.
We are looking for a surface treatment or coating that would provide corrosion resistance. Long term solution is most likely using a copper alloy.

grayseal

 

[gariartola]

Is the water you use in the boiler distilled? Could the chlorides or sulfides that are in the water you boil be influencing the corrosion behaviour of the aluminum?

 

[grayseal]

gariartola,

The water is distilled.

grayseal