Tribological performance of thin organic permanent coatings deposited on 55%Al-Zn coated steel - influence of coating composition and thickness on friction and wear
P. Carlsson et al., Tribological performance of thin organic permanent coatings deposited on 55%Al-Zn coated steel - influence of coating composition and thickness on friction and wear, WEAR, 250, 2001, pp. 1075-1084
Dry lubricants are today increasingly being used in various types of sheet
metal forming operations. Among these, permanent coatings, based on organic
resins are the only lubricants which have the potential to increase the fo
rmability without additional lubrication, serve as temporary corrosion prot
ection during transportation and, finally, serve as a pre-treatment before
subsequent painting.
In the present study, the influence of coating composition and thickness on
the friction and wear behaviour of different thin organic permanent coatin
gs deposited on 55%Al-Zn coated steel sheet have been evaluated by various
types of laboratory tests. Surface profilometry, scanning electron microsco
py (SEM), Auger electron spectroscopy (AES) and time-of-flight secondary io
n mass spectrometry (ToF-SIMS) were used in order to characterise and model
the tribological behaviour of the coatings.
The results obtained show that the tribological properties of thin organic
permanent coatings are strongly influenced by the coating thickness. In ord
er to reduce problems associated with high friction and galling, the coatin
g must be deposited with a uniform thickness, i.e. uncoated regions must be
avoided. Furthermore, the addition of various types of additives can be us
ed in order to further improve the tribological performance of these types
of coatings. (C) 2001 Elsevier Science B.V. All rights reserved.