Solid Lubricants as Friction Modifi ers 193
and long contact times are encountered. A profi le of oxidation characteristics provides a comparison
of oxidation stability between boron nitride and graphite (see Figure 6.13). The ability for boron
nitride to remain intact at a very high temperature makes it ideal for applications that require a long
residency time for lubricant coating.
108
106
104
102
100
98
0 200 400 600 800
Universal V2.3C TA Instruments
1000
Temperature (°C)
Weight (%)
0.2
0.0
−0.2
−0.4
−0.6
Residue:
107.2%
(12.72 mg)
Derivation weight (%
°C)
Derivation weight (%
°C)
110
100
90
80
70
60
50
40
30
20
10
− 10
0
0 200 400 600 800 1000
1.2
1.0
0.8
0.6
0.4
0.2
0.0
−0.2
Weight (%)
Temperature (°C) General V4.0D DuPont 2100
0.8139%
691.17°C
−7.517%
(−0.8918 mg)
0.3150%
(0.03737 mg)
FIGURE 6.13 Comparison of peak oxidation temperatures of boron nitride and graphite. (From Acheson
Colloids test data.)