coefficient A/ = 0.126. The fraction removed (1 -2) systematically increases with
increasing sliding speed and decreasing friction coefficient (Figure 3-2b).
sliding seed
a) (irm/s) b)
0.1 vP=0.0006 1/s m 10
go=0.0075
l =0.1260
C30
50
0 1
10 100 1,000 10,000 10 30 50 75100 303 513 1,000
time (seconds) speed (pm/s)
Figure 3-2 a) Pin-on-disk/reciprocating midpoint model (eqn 2.11) fit to average
Heimberg et al. data (Figure 3-1). b) Fraction removed (1-A) parameter as a function of
sliding speed for model fit.
Model fits to the data in Figure 3-2 are also performed using two additional gas-
surface adsorption models. Model derivation, fits to the data and discussion using both
Henry's Law and the Elovich adsorption model expressions are included in Appendix B
and C.
The fit of the pin-on-disk/reciprocating midpoint model (eqn 2.11) to the constant
speed and dwell tests performed by Heimberg et al. is shown in Figure 3-3a. This model
fit gives a deposition term vP=0.00067 s-1, a nascent surface friction coefficient
/Po = 0.0057, and a covered surface friction coefficient /u = 0.136. The removal fraction
(1 2) systematically increased with decreasing dwell times and decreasing friction
coefficient (Figure 3-3b).
S
0
S
S
......