CNC Machine Manufacturer:
A CNC manufacturer and regular customer of Alpha was experiencing hardcoat (Type III) burning issues with a particular part from a previous anodizer. The alloy of the component was 6061, which we rarely experience any burning of hardcoat components in our tightly controlled processes.
Much to our surprise, our team had two consecutive orders experience some burning on a small number of parts. We double checked our process chemistry and it was well within specifications. Our team also rechecked the surface area calculations for current density and they were precise for that alloy. No other hardcoat jobs had any burning issues. At that point we determined that there may have been a material issue contributing to the problem.
Alpha used a handheld XRF analyzer which provides non-destructive element analysis. The results were enlightening in that the component from our customer was specified as 6061 alloy but had significantly higher amounts of silicon and three times the amount of magnesium you would expect to find. Magnesium and silicon are common alloying elements but can contribute to hardcoat burning. With this new data we were able to adjust the exact time and current density needed to avoid burning.
We have been able to process multiple orders of the customer's parts without burning. They are very satisfied.