Lubricant Additives

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.)