Greetings! I'm wondering if any of the metallurgists out there can tell me of a quick and easy method for measuring porosity in castings (typically zinc and aluminam)? Of course I realize there probably isn't a truly 'quick and easy' method but am interested to know how I would go about measuring porosity, equipment involved, time required, etc. I'd like to set up some sort of incoming inspection on customer supplied castings but really don't even know where to start.

I am only familiar with destructive methods, or limiting the inspection to machined areas. The porosity acceptance criteria is typically a maximum size and quantity per area.

Is porosity a concern from a structural strength perspective, a potential leak path or other?

If it is a strength concern, I believe that x-ray inspection may be used, but I am not experienced in that area.

Greetings! I'm wondering if any of the metallurgists out there can tell me of a quick and easy method for measuring porosity in castings (typically zinc and aluminam)? Of course I realize there probably isn't a truly 'quick and easy' method but am interested to know how I would go about measuring porosity, equipment involved, time required, etc. I'd like to set up some sort of incoming inspection on customer supplied castings but really don't even know where to start.

X-ray may not be able to resolve microporosity. It will see marco or gross voids for sure.

The best method is destructive. Slow and expensive. Section the part, polish and perfrom image analysis for % voids. There are vendors that can set you up iwith all equipment, ncluding training. Just ask if you need some links.

If you machine the part you could count voids per unit area on the machined face I suppose. It would be fast and easy.

Resonance inspection is coming along but is still R&D. Ask if you want a link, they are looking for R&D partners.

If the part is small and porous enough you may be able to do something with density (weigh in water, weigh in air, compare to theoretical density)

How about the vendor, we are a foundry and customers always push these things back to us. What can they do for you?

Do they understand the porosity spec? How do they check before they ship? Why do you have to check? Please don't tell me these castings come from China!