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Astronuc
#3
Oct29-05, 07:53 PM
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Yes, in general it is true that alloys have differences in thermal properties, e.g. lower thermal conductivity, than pure elements. Some examples - thermal conductivities of Fe vs stainless steels, and Ti vs Ti-6V-4Al

Fe (pure) - Thermal Conductivity 76.2 W/m-K (529 BTU-in/hr-ft-F)

400 series stainless steel
24.9 W/m-K 173 (BTU-in/hr-ft-F) 100C
28.6 W/m-K 198 (BTU-in/hr-ft-F) 500C

300 series stainless steel
16.2 W/m-K 112 (BTU-in/hr-ft-F) 100C
21.4 W/m-K 149 (BTU-in/hr-ft-F) 500C

Thermal Conductivity
Ti (pure) - 17 W/m-K (118 BTU-in/hr-ft-F)

Ti6Al4V (grade 5) - 6.7 W/m-K (46.5 BTU-in/hr-ft-F)


If the alloying is very slight - e.g. 1-2%, then the differences may not be significant. For some Zr-alloys, alloying actually increases thermal conductivity.

Thermal Conductivity
Zr (pure) - 16.7 W/m-K (116 BTU-in/hr-ft-F)

Zircaloy-2 - 21.5 W/m-K (149 BTU-in/hr-ft-F), Zr-2 is about Zr-1.5Sn-0.2Fe-0.1Cr-0.05 Ni-0.12O

Grade 702 - 22 W/m-K (153 BTU-in/hr-ft-F). Zr-4.5Max Hf - 0.2(Fe+Cr)-0.16O

One could try comparisons of elements and alloys on Matweb, which is from where the thermal conductivity data were taken