Investment Casting Lot Traceability

[McKagan13]

I work in an industry where lot traceability of each individual component is of the utmost importance. To control lot ID during the casting process, the lot ID is hand etched into the wax and thus transferred to the part. The part once casted is then laser etched and the original lot ID is belted off. This process really bugs me. Im thinking of switching to a cast-in lot code where a ID tab is placed in the wax prior to casting. This process does not eliminate the human element though, and still provides an opportunity for lot tracebility problems. The idea of laser etching the wax prior to casting is also being investigated.

Those that utilize investment casting or similar process, how do you provide lot traceibility per component?

 

[swall]

First of all, how are you defining a lot? Is it one "tree" of castings, is it all trees of castings poured from one ladle or is it all castings poured from a melt?

 

[McKagan13]

Sorry for the lack of clarity. The lot is defined as 1 "tree" of casting. Generally 6-8 components.

 

[MikeHalloran]

Is there a nonfunctional area on the part where you could emboss a recess and a lot number in the wax, so it wouldn't be 'belted' off?


Mike Halloran
Pembroke Pines, FL, USA

 

[McKagan13]

Mike,

That is what I referred to as a cast-in lot code. Essentially a tab is placed in the wax with the lot ID on it and thus be transferred to the casting.

Again, ideally I would like to minimize the human element as much as possible. Placing each individual lot code tab in the wax as well as the cost of each tab almost off-sets quality/cost savings.

Thanks

 

[MikeHalloran]

I was thinking of pressing a warm numberall stamp into a molded recess in each pattern before attaching them to the tree. You could get a self-incrementing model to make each and every pattern unique, or manually increment after doing one tree's patterns.





Mike Halloran
Pembroke Pines, FL, USA

 

[ajack1]

The two methods I have seen used are firstly as Mike Halloran describes so you end up with a sort of milled pocket below the face that gets machined or belted with an ID number in it or the ID number is above the surface on an area that does not get machined.

 

[Dtuck]

I'm probably a little late on this one, but could a rotating code insert be worked into the part somewhere? If so, what material would it have to be made out of?