ICI Member Benefits Do You Have a Technical Question? by Nora D’Ambra, Business Administrator T


o better service the investment casting industry, the Investment Casting Institute has developed


“Ask The Experts”. This service allows members and non-members alike to raise technical issues they are currently confronted with to the Institute’s Technical Committee. The Committee will try to post its responses(s) within 5 business days. Not only does the questioner get the answer to the question via email, but questions and responses are made available to all Institute Members in the Members-Only area. Past answered questions are


available on the “Ask The Experts” page of the Members Only area.


Previously Asked Questions Q: Q: Q: Q:


We are pouring S7 and are having gas hole problems. We


have trialed low nitrogen material using an Argon blanket to no avail. Any other tricks with this material?


With regard to vacuum heat treatment, does it improve me-


chanical properties, especially ductili- ty and toughness? I know that it totally eliminates surface oxidation of castings and associated defects. I have not been able to get any information on this.


Currently, I am working on a new leaching autoclave using


potash but I have had difficulty finding the right leaching cycle (core material remains in the parts). I’m looking for in- formation regarding leaching with pot- ash, even if it’s not for the same appli- cation. Could you help me by providing some information about the use of pot- ash (parameters, used process…)?


On a well-established, robust process, we suddenly began


witnessing perfect little pin holes in the resulting parts. We have never had this problem before, and they look exactly like the gas (air entrapment)as described


®


in your Atlas of Casting Defects book page 9. We cannot figure out why all of a sudden this is starting to happen we have not changed anything in our pro- cess. We pour right at the cup and the venting is the same we have used for years. The only thing different is that we have a new employee helping with the pouring. Could this possible cause the problem? Also is there anything we can add


to 440-C to help de-gas it to help fix this if that is what is going on and if so why would we all of a sudden have to use an additive to de-gas when we never have before? We have not changed anything in the shelling process, it is all the same as before we started to get these holes. They are causing us to have a lot of scrap in our parts. Just trying to cover all our bases and get this figured out. Any infor- mation you can give us on this would be greatly appreciated.


Q:


Q: Q:


Our company shies away from 430SS as past experience has


shown that the alloy is prone to crack- ing. Is this especially true of this alloy? And how would one work around this problem?


We are experiencing cracking on the edge of an A357 cast-


ing. The defect only occurs on one of the four parts in the mold cluster. Any ideas?


I want to understand more on the use of plasticizers in the


formation of investment casting patterns. I am currently writing a Ph.D. proposal on the production of investment casting patterns from thermoplastics. Is there anyone with which I can contact to dis- cuss plasticizers in wax patterns? Are there any reference materials available?


Our Assurance of Your Anonymity All topics addressed through Ask the Experts are treated as Company Confidential Information. Each ICI staff


Natural Gas Propane • Butane % O2 Trim


Manual or Automatic Hearth Car Movement


Armil CFS, Inc. 15660 La Salle St., South Holland, IL 60473 708-339-6810 office • 708-339-0517 fax email: info@armilcfs.com www.armilcfs.com


January 2019 ❘ 7


member is bound by a confidentiality agreement on file in the Institute’s corporate office. Questions sent to Ask the Experts are rewritten, removing all references to the identity of the submitting company and/or individual. The resulting question is then provided to the Technical Committee with no reference whatsoever to Member name or location. The Technical Committee reviews the inquiry and returns a response to the Institute. The ICI responds directly to the submitter and posts the question and response to the Ask the Experts page of the website. So if you have a technical question,


check out “Ask The Experts” on the Investment Casting Institute’s website at www.investmentcasting.org.


Tru-Heat Afterburner 5 - 1


Door Safety Rating


®


1400°– 2200°F WRF (Wax Reclamation Furnace)


Fiberfrax™ Lining


Custom Hearth


Positions to Meet Mold


Dimensions


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