Porosity Check in HPDC AL blocks

[CstgCurious]

The application is high pressure die cast aluminum engine blocks. We perform x-ray checks on sections of the casting to check for gas and shrinkage porosity in critical leak path areas. A large effort is being placed into moving this porosity with parameters and design, but the cost involved in this x-ray examination process is heavy. Castings must be cut in order to get a good x-ray image around the steel liners. The cost is incurred both in cutting blades(going through steel and AL) as well as internal scrap.

Could anyone recommend another practice that would be non destructive yet still define exactly where the porosity is located?

 

[TVP]

Are you performing computer simulation on the casting process?

 

[GregLocock]

Our supplier used to X ray his LPDC aluminium wheels. I'm not sure if we specified that X ray was the method, I suspect so.

However I have heard of gravity cast wheels being checked via a leakage method, that sounds less destructive and more relevant than X rays, but of course you have to have finished machining the area before you can test it.








Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[CstgCurious]

Yes, we run casting computer simulations as part of a daily routine. Been in production for 6 months - still fairly new and working out the bugs.

We perform leak tests as well, but we do not leak until machined(as you stated above). This is machined at our customer, therefore external scrap if it is present.

 

[TVP]

Computed tomography has been developed into a practical NDE technique. Use the following google search to obtain more information:

http://www.google.com/search?hl=en&q=computed+tomography+casting&aq=f&oq=