2^2 



Table 251 

 THERMAL CONDUCTIVITY, METALS AND ALLOYS 



The coefficient k is the quantity of heat in small calories which is transmitted per second through 

 a plate one centimeter thick per square centimeter of its surface when the difference of tempera- 

 ture between the two faces of the plate is one degree Centigrade. The coefficient k is found to 

 vary with the absolute temperature of the plate, and is expressed approximately by the equation 

 kt = &<£i + o.(t — /o)]. k is the conductivity at to, the lower temperature of the bracketed pairs 

 in the table, kt that at temperature t, and a is a constant, kt in g-cal. per degree C per sec. across 

 cm cube = 0.239 x kt in watts per degree C per sec. across cm cube. 



Substance 



Aluminum. . 



Antimony .... 

 Bismuth 



Brass 



" , yellow. . 



" ,red.... 



Cadmium, pure 



Constantan. . 

 (60 Cu+40 Ni 

 Copper,* pure 



German silver 



Gold 



Graphite . . 

 Iridium . . . 

 Iron,f pure 



Iron, wrought 



" steel, i f ; 



C 



Lead, pure. . . 



Magnesium. 



Manganin .... 



" (84CU+4 



Ni 12 Mn) 



t°C 



-160 



18 



100 



200 



400 



500 



600 



o 



100 



-186 



18 



100 



-160 



17 



■160 



ii 



100 



18 



100 



•160 



18 



100 



17 

 17 

 17 

 18 

 100 



— 160 



18 

 100 



18 

 100 



— 160 o 



ij 



IOO 

 oto| 



— 160 



18 



TOO 



514 

 480 

 492 



545 



760 



885 



01 



0442 1 



0396 / 



025 



0194 1 



0161 / 



181 



260 



204 



246 



2 39. 



215 



0540 



0640 



079 



918 



908 



070 



705 



037 



141 



161 



■151 

 .152 

 . 144 1 



•143/ 

 .108I 

 .107/ 

 .092 

 .083 \ 

 .081 / 



•370 



■035 

 • 5i9 \ 

 • 0630 / 



Substance. 



Mercury .... 



Molybdenum 

 Nickel 



Palladium.. . 



Platinum.. . . 



Pt 10 % Ir . . 

 Pt 10% Rh . 

 Platinoid . . . 

 Potassium. . . 



Rhodium. . . . 

 Silver, pure.. 



Sodium 



Tantalum. . . 



a 

 a 



Tin ! ". ! 



" , pure — 

 Tungsten. . . . 

 Tungsten. . . . 



Wood's alloy 

 Zinc, pure. 



+ 0055 



- .0001 



— . OOO3 2 



- . OOO95 



—.00047 

 +.OOIO 



+ ■ 0005 I 



+.0002 

 +.0002 



-.OOI3 

 — .OOIO 



—.OOOI7 



-.OOI2 

 —.OOOI 



+.OOO32 

 - . OO069 



+.OOO23 

 +.OOOI6 



—.OOOl6 



OJ <j 



References: (1) Lees, Phil. Trans. 1908; (2) Jaeger and Diesselhorst, Wiss. Abh. 

 Phys. Tech. Reich. 3, 1900; (3) Angell, Phys. Rev. 191 1; (4) Lorenz; (5) Macchia, 

 1907; (6) Barratt, Pr. Phys. Soc. 1914; (7) H. F. Weber, 1879; (8) Hornbeck, Phys 

 Rev. 1913; (9) Worthing, Phys. Rev. 1914; (10) Worthing, Phys. Rev. 1917. 



* Copper: 100-197 C, kt = 1.043; 100-2 

 ing; for reference see next page). 



flron: 100-727 C, kt = 0.202; 100-912 , 0.1 

 Smithsonian Tables. 



, 0.969; 100-370 , 0.931; 100-541 , 0.902 (Her- 

 100-1245 , 0.191 (Hering). 



