Thermal Contact Conductance of Lead Ferrite and Boron Nitride

1976 ◽  
Vol 98 (2) ◽  
pp. 331-332 ◽  
Author(s):  
L. S. Fletcher ◽  
W. R. Ott
2006 ◽  
Vol 128 (4) ◽  
pp. 319-323 ◽  
Author(s):  
Zongrong Liu ◽  
D. D. L. Chung

Wax (predominantly tricosane paraffin wax, with a melting temperature of 48°C) filled with hexagonal boron nitride (BN) particles (5-11μm) was found to be an effective phase-change thermal interface material. The thermal contact conductance, as measured with the interface material between copper surfaces, decreased with increasing temperature from 22to48°C, but increased with increasing temperature from 48to55°C. The melting of the wax enhanced the conductance, due to increased conformability to the mating surfaces. For a given BN volume fraction and a given temperature, the thermal contact conductance increased with increasing contact pressure. However, a pressure above 0.30MPa resulted in no significant increase in the conductance. The conductance increased with BN content up to 6.2vol.%, but decreased upon further increase to 8.6vol.%. The highest conductance above the melting temperature was 18×104W∕m2.°C, as attained for a BN content of 4.0vol.% at 55°C and 0.30MPa. Below the melting temperature, the highest conductance was 19×104W∕m2.°C, as attained for a BN content of 6.2vol.% at 22°C and 0.30MPa.


1999 ◽  
Vol 122 (2) ◽  
pp. 128-131 ◽  
Author(s):  
Yunsheng Xu ◽  
Xiangcheng Luo ◽  
D. D. L. Chung

Sodium silicate based thermal interface pastes give higher thermal contact conductance across conductor surfaces than polymer based pastes and oils, due to their higher fluidity and the consequent greater conformability. Addition of hexagonal boron nitride particles up to 16.0 vol. percent further increases the conductance of sodium silicate, due to the higher thermal conductivity of BN. However, addition beyond 16.0 vol. percent BN causes the conductance to decrease, due to the decrease in fluidity. At 16.0 vol. percent BN, the conductance is up to 63 percent higher than those given by silicone based pastes and is almost as high as that given by solder. Water is almost as effective as sodium silicate without filler, but the thermal contact conductance decreases with time due to the evaporation of water. Mineral oil and silicone without filler are much less effective than water or sodium silicate without filler. [S1043-7398(00)00402-3]


2002 ◽  
Vol 124 (3) ◽  
pp. 188-191 ◽  
Author(s):  
Yunsheng Xu ◽  
Xiangcheng Luo ◽  
D. D. L. Chung

Polyethylene-glycol-based thermal interface paste containing trifluoroacetic acid lithium salt (1.5 wt. percent optimum) and boron nitride particles (∼18.0 vol. percent optimum), as well as water and N, N-dimethylformamide for helping the dissociation of the salt to release Li+ ions, gives thermal contact conductance that is almost as high as that given by Sn-Pb solder, similar to that given by boron nitride particle filled sodium silicate, and much higher than that given by boron nitride particle filled silicone.


10.2514/3.870 ◽  
1997 ◽  
Vol 11 ◽  
pp. 129-140
Author(s):  
B. Merci ◽  
J. Steelant ◽  
J. Vierendeels ◽  
K. Riemslagh ◽  
E. Dick ◽  
...  

10.2514/3.871 ◽  
1997 ◽  
Vol 11 ◽  
pp. 141-145
Author(s):  
Andreas Haselbacher ◽  
Jiri Blazek ◽  
S. R. Mirmira ◽  
E. Marotta ◽  
L. S. Fletcher

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