Subject: Re: Copper Alloys
From: Ang Lee
Date: Fri, 09 Apr 2010 14:19:25 -0500
To: Rob Reilly , Ang Lee
CC: Lawrence J Allen , Fernanda G Garcia

Hi Rob and all
Here is the result for C19400.
I think it is an excellent choice. It combines a high strength and good conductivity.
 
Also, keep that in mind that the top plate has 1" thickness. For the structure load , 1/3" is more than from bottom is more than sufficient. Therefore, you could
considered 1/3" from bottom mainly for the structure purpose and 2/3" from top will be mainly for heat distirbustion. The calcuation indicates that the thermal stress is indeed
very low at 1/3" from bottom and satified the code requiement even under 50% contact case (this case is very close to 0% contact).  If you could maintain a good contact, the current design should be
adequate by using C19400 .
regardsm
Ang
 
 
 
 
 
----- Original Message -----
From: Ang Lee
To: Rob Reilly
Cc: Lawrence J Allen ; Fernanda G Garcia
Sent: Friday, April 09, 2010 8:58 AM
Subject: Re: Copper Alloys

Rob,
Thanks for the point it out !
I've checked alloys thermal conductivity for B169 C61400 & B171 C63000.
 K=~57 W/mK for C61400 and K=~37 W/mk for c63000
Therefore, it is too low (Compared with SB-187, K=~380).  For 100% contact case, it is still ok. But for 50% contact, the temperature is too high ~1100 K due
to the lower conductivity. Therefore,both c61400 and c63000 is NOT suitable due to its thermal conductivity, even it has a high strength at the elevated temperature.
 
So, I'm check othere possible material/options
 
1) One of them is C19400__high strength modified copper Cu=2.35 Fe-0.3P-0.12 Zn. Please check ! it has a 18 ksi yield strength at (500 F) and K=260 W/m K for the conductivity.
It is somewhere between C6xxxxx and C102XXX  for its conductivity and strength. I'm checking it and will keep all of you posted soon.
 
2)  or we could make a bi-metal type for the top plate: maybe 0.5" for the c61400  for strength requirement and 0.5" for C102XX(pure copper) for the heat desserpation reason. (then, we have both high strength and conductivity. I did not know it will work or not yet. How do we/you  make there two piece copper together with a good bond ?
 
3) Rob: if you could talk to some venders cand see if with some special temper, we could get higher  strength at an elevated temperature like yield stress=25 ~30 ksi at T=400-500 F for C102XXX type copper.  ASME  Table Y gives much high yield strenght , Sy~30 ksi for (T=400F) for smls pipe with H80 temper (SB-42,SB-75, SB111) for C10200? If we could get it for the plate,that will be it!
 
4) other? active cooling ?
 
 
let's one at time, I'll update you for # 1 soon
 
Ang
 
 
 
 
 
 
 
 
----- Original Message -----
From: "Ang Lee" <alee@fnal.gov>
To: "Rob Reilly" <reilly@fnal.gov>
Cc: "Lawrence J Allen" <allen@fnal.gov>; "Fernanda G Garcia" <fgarcia@fnal.gov>
Sent: Thursday, April 08, 2010 8:12 AM
Subject: Re: Copper Alloys

> Hi Rob,
> I'll checking into it and get it back to you.
> Ang
>
> ----- Original Message -----
> From: "Rob Reilly" <
reilly@fnal.gov>
> To: "Ang Lee" <
alee@fnal.gov>
> Cc: "Lawrence J Allen" <
allen@fnal.gov>; "Fernanda G Garcia"
> <
fgarcia@fnal.gov>
> Sent: Wednesday, April 07, 2010 4:59 PM
> Subject: Copper Alloys
>
>
>> Ang,
>> Looking up alloys B169 C61400 & B171 C63000, I see they have increased
>> amounts of Al, Ni & Fe. Does the addition of these elements change the
>> thermal conductivity significantly from B187 C11000? Should the FEM take
>> this into account?
>> Rob
>>
>

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