Casting 'Super Invar'
Casting 'Super Invar'
(OP)
Does anyone know, or can anyone point me to resources that might address, Casting super Invar?
As back ground, we use a large cast Invar 36 component as a major structural piece on one of our microscopes, in order to minimize thermal drift.
I've been wondering for a while now, given that we're casting it anyway, whether casting it out of super Invar might give us even better drift performance without too much of a cost impact.
I don't want to propose it until I have at least a vague notion that it's a realistic option.
I've done various Google searches about it but haven't found much definitive. I know that the composition of Super Invar Alloy is 32% Nickel, 5.5% Cobalt and the remaining balance Iron but I'm not sure what that Cobalt does to it's casting properties.
I believe our current casting vendor mixes the invar themselves rather than melting down invar ingots, though I'm not 100% sure.
Thanks.
As back ground, we use a large cast Invar 36 component as a major structural piece on one of our microscopes, in order to minimize thermal drift.
I've been wondering for a while now, given that we're casting it anyway, whether casting it out of super Invar might give us even better drift performance without too much of a cost impact.
I don't want to propose it until I have at least a vague notion that it's a realistic option.
I've done various Google searches about it but haven't found much definitive. I know that the composition of Super Invar Alloy is 32% Nickel, 5.5% Cobalt and the remaining balance Iron but I'm not sure what that Cobalt does to it's casting properties.
I believe our current casting vendor mixes the invar themselves rather than melting down invar ingots, though I'm not 100% sure.
Thanks.
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What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?





RE: Casting 'Super Invar'
http://www.cartech.com/techcenter.aspx?id=1692
RE: Casting 'Super Invar'
For heat treatment adopt the water quench route and followed by stress relieving.
If you need more details,I shall share whatever little I know.
Good Luck!
_____________________________________
"The richer we have become materially, the poorer we have become morally and spiritually." Martin Luther King Jr
RE: Casting 'Super Invar'
Below link to a book (p.587) and other material that you may find usefull.
RE: Casting 'Super Invar'
RE: Casting 'Super Invar'
The obvious thing would be to speak to our vendor but we have new purchasing staff and the whole thing's got a bit political so I just wanted to do some research without upsetting our supply chain
I wanted to get a feel for if casting super invar instead of invar 36 is likely to be significantly more difficult/expensive.
Arunmrao, I won't actually be doing the casting myself though so don't be too impressed!
cloa, stupid as it sounds my initial attempts at Google searches didn't turn up anything of much help from Carpenter, however via your link I've found some useful stuff, thanks.
(My next pet project is to see how much it would cost to replace the big slabs of Granite our stuff sits on with Zerodur or something!
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Casting 'Super Invar'
_____________________________________
"The richer we have become materially, the poorer we have become morally and spiritually." Martin Luther King Jr
RE: Casting 'Super Invar'
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Casting 'Super Invar'
The name is changed now to Nickel Institute. Sorry about the confusion. I have provided a search link for Invar.Please refer to them.Hope you find it useful.
_____________________________________
"The richer we have become materially, the poorer we have become morally and spiritually." Martin Luther King Jr
RE: Casting 'Super Invar'
Is there any Ti or Al in your castings? Often these are added for deoxidation. You might be better off with Nb to tie up O, N, and C.
You anneal, water quench, and then bake at 400F for a few cycles? I am going from memory but that is what I think we used to use.
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Plymouth Tube
RE: Casting 'Super Invar'
I can't remember what heat treat we do on this cast part but we've built nearly 200 and I don't think we've had any issues.
I know on some other machined Invar parts we do major machining, then do heat treat then do light finish machining per this note.
"AFTER MAJOR MACHINING IS COMPLETE, STRESS RELIEVE AS FOLLOWS: HEAT
TO 1500F (815C), HOLD FOR 30 MINUTES, WATER QUENCH. REHEAT TO 600F
(315C), HOLD FOR ONE HOUR, AIR COOL. FINISH MACHINING IS PERMISSIBLE
AFTER HEAT TREAT, .030 MAXIMUM MATERIAL REMOVAL FROM ANY SURFACE."
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?