are results of friction experiments in a ball-on-flat device as a function of the load.
Paraffin oil, with additions of 0.5 and 1 wt% WS 2 fullerene-like particles, was applied as
a lubricant. The most important point is the load where the friction coefficient
suddenly increases, as this deflection point describes the load capability of a friction
pair. The critical load to seizure of the metal surface increases with the addition of only
0.5 wt% WS 2 , from 270 to 430 N. The advantage of a further increase in WS 2 content
was minimal, as higher concentrations appear to have only a minor influence. These
results justify the statement that such fullerene-like particles outperform conventional
lubricants. Similar positive effects were observed using WS 2 particles as an addition to
metal-working fluids applied to high-precision shaping techniques such as drilling or
lathing. The advantages of such an application are 2-fold:
Due to reduced friction, the applied forces and temperature are each reduced.
When narrow-tolerance parts are involved, a controlled temperature is essential in
order to obtain the intended dimensions.
The metal-working fluid requirements are reduced and the lifetime of the cutting
tools is extended.
Reduced friction was observed when impregnating fullerene-like particles into
self-lubricating solid films. The initial attempts to fill nickel–phosphorus electroless
coatings with fullerene-like WS 2 particles were successful and improved the
properties of these self-lubricating coatings. Some typical results of a tribological
test versus time are shown in Figure 5.31, where the friction coefficient of a pure
nickel–phosphorus layer is compared to that of a layer of the same material, but
containing some dispersed WS 2 fullerenes. During the first two cycles, there was
almost no difference between the friction of the layers, with or without WS 2 filling.
Figure 5.30 Tribological properties of paraffin
oil with WS 2 fullerene-like particle addition.
Effect on friction coefficient compared to a
lubricant without such additions, determined
with a ball-on-flat device as a function of the
load. The load where the friction coefficient
suddenly increases is described as the load
capability of a friction pair. The critical load to
seizure increases with the addition of WS 2 [17].
112j 5 Nanotubes, Nanorods, and Nanoplates
Paraffin oil, with additions of 0.5 and 1 wt% WS 2 fullerene-like particles, was applied as
a lubricant. The most important point is the load where the friction coefficient
suddenly increases, as this deflection point describes the load capability of a friction
pair. The critical load to seizure of the metal surface increases with the addition of only
0.5 wt% WS 2 , from 270 to 430 N. The advantage of a further increase in WS 2 content
was minimal, as higher concentrations appear to have only a minor influence. These
results justify the statement that such fullerene-like particles outperform conventional
lubricants. Similar positive effects were observed using WS 2 particles as an addition to
metal-working fluids applied to high-precision shaping techniques such as drilling or
lathing. The advantages of such an application are 2-fold:
Due to reduced friction, the applied forces and temperature are each reduced.
When narrow-tolerance parts are involved, a controlled temperature is essential in
order to obtain the intended dimensions.
The metal-working fluid requirements are reduced and the lifetime of the cutting
tools is extended.
Reduced friction was observed when impregnating fullerene-like particles into
self-lubricating solid films. The initial attempts to fill nickel–phosphorus electroless
coatings with fullerene-like WS 2 particles were successful and improved the
properties of these self-lubricating coatings. Some typical results of a tribological
test versus time are shown in Figure 5.31, where the friction coefficient of a pure
nickel–phosphorus layer is compared to that of a layer of the same material, but
containing some dispersed WS 2 fullerenes. During the first two cycles, there was
almost no difference between the friction of the layers, with or without WS 2 filling.
Figure 5.30 Tribological properties of paraffin
oil with WS 2 fullerene-like particle addition.
Effect on friction coefficient compared to a
lubricant without such additions, determined
with a ball-on-flat device as a function of the
load. The load where the friction coefficient
suddenly increases is described as the load
capability of a friction pair. The critical load to
seizure increases with the addition of WS 2 [17].
112j 5 Nanotubes, Nanorods, and Nanoplates