Rank Copper, Brass and Bronze by Thermal Conductivity

[Fishworks]

TL;DR

Can I get help ranking Copper, Brass and Bronze by Thermal Conductivity?

Hi,

Can I get help ranking Copper, Brass and Bronze by Thermal Conductivity?

This stuff below says Copper is the best Thermal Conductor, and Bronze is the worst.
https://en.wikipedia.org/wiki/List_of_thermal_conductivities
https://www.engineersedge.com/properties_of_metals.htm
https://www.metalsupermarkets.com/which-metals-conduct-heat-best/
https://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html

Here below says Bronze is the best Thermal Conductor, and Brass is the Worst.
https://at-machining.com/bronze-vs-brass-vs-copper/#:~:text=In terms of thermal conductivity,/hr-ft²-ºf.
https://www.rapiddirect.com/blog/brass-vs-bronze-vs-copper/

Here is says Copper is the best Thermal Conductor, and Brass is the Worst.
https://neutrium.net/heat-transfer/thermal-conductivity-of-metals-and-alloys/

I am confused.

 

[Bystander]

Specific alloy compositions are what?

 

[f95toli]

Pure copper is the best thermal conductor of the three.

However, there are many different grades of copper, brass and bronze and the thermal conductivity between different grades of the same alloy can be very different.
Typically, the type of copper used to machine parts is not very pure at all, it is an alloy; simply because really pure copper is typically too soft to be useful (and expensive).
It also depends on the temperature; Oxygen Free High Conductivity Copper is a much,much better thermal conductor than "regular" copper at low temperature; but at room temperature the difference is much smaller to the point where it is usually insignificant.

Hence, you need to be more specific.

 

[Fishworks]

On Engineering Toolbox
Copper at 0-127c is 401-392 w/mk
Brass (70%cu 30%zn) at 20c is 111w/mk
Bronze (75%cu 25%zn)at 20c is 26w/mk

On Neutrium.net
Copper at 20c is 401w/mk
Bronze at 20c is 188w/mk
Brass at 20c is 144w/mk

They are providing conflicting info.
In your opinion, which of the above sources I provided is best, reliable or most accurate?

 

[Fishworks]

I hope its not too late but I edited my latest response. Please do check it out.
At this point, i am leaning towards using Engineering Toolbox for reference. Many Thanks

 

[Bystander]

There are numerous, not infinite but close, Cu-Sn/Zn alloys; https://en.wikipedia.org/wiki/Brass. Cartridge brasses, music/acoustic brasses, naval brasses/bronzes, phophor-bronzes....

Hence the need request/s for specificity.

 

[Astronuc]

Bronze (75%cu 25%zn)at 20c is 26w/mk

Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin (Sn) and often with the addition of other metals (including aluminum, manganese, nickel, or zinc). Brass consists of a mixture of copper and zinc, and as Bystander indicated, composition is a critical factor here.

Cu and Zn are neighbors in the periodic table, while Sn (Z = 50, A ~ 118.71). Larger, more massive atoms do not 'conduct' heat very well compared to lighter atoms (phonon conduction).

One also has to consider solid solution vs precipitation-based alloys (which usually means intermetallics), which interfere with heat transfer. In the case of precipitation hardened alloys, thermal conductivity can be improved if the alloy atoms are dispersed as fine precipitates in the main/bulk, here Cu, matrix.

Different kinds of commercial bronze alloys
https://www.advancebronze.com/bronze-alloy-chart/

A good source of information on Cu and Cu-alloys is the Copper Development Association, Inc.
https://copper.org/resources/properties/
https://copper.org/applications/marine/other-copper-alloys/brasses/
https://copper.org/resources/properties/microstructure/cu_tin.php (aka Bronzes)

https://www.copper.org/applications/industrial/DesignGuide/selection/elect02.html

 

[Nik_2213]

It's not just the initial composition, but the mechanical handling.

I'd expect 'work-hardened' copper to have a lower thermal and electrical conductivity than the 'fresh' stuff.