Finding material which can fulfill certain requirements

[tengkimyen]

Dear all,

I am looking for a kind of material which can fulfill certain requirements.

1. Low electrical resistivity =< 178 microhm-cm @ 20 degree
2. High thermal conductivity => 6.7 W/m-k @ 20 degree
3. Low specific heat capacity =< 526.3 J/Kg-K @ 20 degree
4. Low coefficient of thermal expansion =< 9.2 @ 350 degree
5. High hardness => 36 HRC

*Bolded is much more important.

Usage: This material will undergo 4 bar pressure force and 500 degree temperature.

Most important to achieve the 2 bold requirement (1 and 4). That is the most important.

Material may not possible to fulfill all criteria, but it is better to achieve as much as possible.

Your suggestion and comment is highly appreciate!

 

[Maui]

Take a look at Lescalloy 15-5 VAC-ARC by Latrobe. It doesn't meet all of your requirements, but it does meet most of them.

http://customer.cartech.com/assets/documents/datasheets/15-5.pdf

Maui

 

[metengr]

tengkimyen
Think about this, how can you possibly select an alloy with no service information like temperature and environment?

 

[tengkimyen]

Hi Maui,

Thanks for your recommendation. I will take a look and reply back to you.



Hi metengr,

Thanks for the reminder. I just add the service information.

This material will be use for bonding purpose. Therefore, this material will undergo 4 bar pressure force and 500 degree temperature.

Hope this will serve you all better in helping me.

From Teng Kim Yen

 

[tengkimyen]

Hi Maui,

Thanks for the recommendation. The problem with this material is the thermal expansion. When it is raise up to 400 degree, it expand about 11 mm. It is consider out of our spec.

However, thanks for your suggestion. We appreciate it.

From Teng

 

[metengr]

tengkimyen;
What is the environment, corrosion resistance needed ?

 

[EdStainless]

Have you looked at the lowest carbon steel that will make your strength.
You want a steel with low Mn and Cr.
Aside from strength pure Fe comes as closest to your requirements.
A word of warning, all of the low expansion alloys will rust, they are not corrosion resistant.
Though Ti 6-4 may be worth looking at as well. It has low density, low heat capacity, and low thermal expansion.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[MagBen]

Try Carpenter Pyromet® Alloy CTX or Thermo-Span® Alloy.
Pyromet® Alloy CTX is a low expansion superalloy with a CTE about 7.6 ppm/C at 300-400C.
Thermo-Span® Alloy shows about 9 ppm/C at 350C. It is a precipitation hardenable superalloy which exhibits high tensile and rupture strengths, and good thermal fatigue resistance. It offers a significant improvement in environmental resistance over Pyromet® alloys CTX due to the addition of chromium.

 

[EdStainless]

Are you actually looking for the CTE from RT to 375C, or the CTE at 375C?
If 15-5PH grows 11mm your work piece must be about 3m long, right?

Either way I would still look at Ti 6-4 or 3-2.5

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[Rustam1]

I recommend the tool material hard alloy WC-Co10% (WC-8%, WC-15%, WC-20% etc.).
Properties as degree C:
1. Low electrical resistivity =18-20 microhm-cm.
2. High thermal conductivity =55-70 W/m-k
3. Low specific heat capacity =210 J/Kg-Kdegree
4. Low coefficient of thermal expansion =5,2-5,5*(10-6)/grad. C
5. High hardness =69-70 HRC.
This material can withstand pressure of 40,000 bar and operates at temperatures of 500 C
But:
-it has a density of 14 g / cm3
-processed by a diamond tool and cubic boron nitride.

The task set is not quite correct.

If this is a long item, it will be necessary to use a quartz tube or rod.

 

[amorrison]

More generally - checkout books by "Ashby" on Amazon.

 

[tengkimyen]

Thanks all. I will study all the material you suggested and reply one by one to you all. Please provide me more if you guys have any ideas.

As for metengr,

The enviroment is normal temperature. IT SHOULD NOT CORROSIVE.

Thanks for your suggestion.

From Teng

 

[WKTaylor]

tengkimyen...

In addition to all the thoughtful comments by everyone else... here some auxiliary comments/ideas.

You may find the following document useful in a limited way. Metal dimensional changes are rarely linear. The following document discusses these changes and lists many material types/alloys and their dimensional change coefficients across a wide range of /\ temperatures. These should be carefully considered when heating and cooling Your tooling... especially from a warpage/thermal-fatigue perspective. May also help You understand how long it could take for Your metal tooling to become fully stable/heat-soaked [especially with significant differences in thickness across the tool].

SAE AIR809 Metal Dimensional Change with Temperature.

CAUTION. Many metals experience measureable contraction or expansion when taken from one heat treat-state [condition] to another [stable] heat treat state [condition].

CAUTION. 'Thermal fatigue' MAY be an issue You will have to deal with in high volume production and high soaking temperatures [75F-to-500F?? or 24C-to-500C???... there is a huge difference in overall expansion/strains]. For this reason the heat-up and cool-down cycles must considered... perhaps even segmenting the tool into shorter elements to minimize over-all expansion/contraction... or perhaps consider ceramic tooling.

Regards, Wil Taylor

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