Parameters Nominal Contact Smooth on rough (30 [mm.sup.2] area) Lubricant Newtonian fluid n = 0.100 Pas and [alpha] = 2.0 10-8 [Pa.sup.-1] Speed 0.1 to 10 m/s Microgeometry Rough on Smooth Mean apparent 1 MPa pressure Materials Steel on Brass Steel [E.sub.1] = 2 [10.sup.11]; [v.sub.1] = 0.3] Brass [E.sub.2] = 1 [10.sup.11]; [v.sub.2] = 0.3 [Rp.sub.e] = 500 Mpa Boundary friction
[f.sub.b] = 0.12 coefficient Table 2: Parameters of the statistical description.
It is because that there are boundary friction
and fluid friction when the speed is slow.
The most common positive effect in the boundary friction
between surfaces with a partially regular microrelief can be explained in relation to the lubrication conditions improved by increasing oil absorption (Schneider 1982, 1998, 2001).
b) Where boundary lubrication cannot be avoided, boundary friction
should be reduced as much as possible through the use of lubricant additives or other methods, such as low friction coatings.
Its computation for mixed and boundary friction
should be based on experimental results.
This difference between the two curves (theoretical and experimental) can be exploited in two directions: the prediction of contact under the conditions of mixed or even boundary mode and also the determination of the rate and positions of wear, knowing as the zones of mixed and boundary friction
are exposed to the wear and that the rate (percentage) of boundary mode (and mixed) in contact is representative of the wear rate .
Wet but not slippery: boundary friction
in tree frog adhesive toe pads [J].
is common in lightly lubricated, slow-moving devices, and is often what we think of as everyday lubrication: The base materials still contact each other, but the effects are mitigated by the lubricant's presence.
The biphasic boundary friction
model proposed in [14-16] quantifies the load sharing between the solid and fluid phases of the porous-permeable cartilage at the contact interface.