β Scribed by E. Bemporad; E. Comis; M. Sebastiani; F. Carassiti; B. Palumbo
No coin nor oath required. For personal study only.
Ball cratering and rotating wheel tests are useful techniques for abrasive wear resistance evaluation of thin coatings.
Nevertheless, such techniques involve significant experimental errors, coming from equipment deficiencies and changes in wear response depending on test parameters.
In case of rotating wheel test, common instrumental errors are: geometryβinduced errors (curved or nonβhorizontal sample surface), alignment errors (misalignment between ball/wheel rotation axis and sample stage) and optical measurement errors.
In the present paper, errors due to crater dimension detection system (penetration depth or crater diameter) and equipment deficiencies (rotating axes misalignment and sample slope) were numerically analysed.
A general expression for volume calculation was obtained, considering axes misalignment and sample slope, and experimentally validated by wear tests on Ti/TiN CAEβPVD coatings and profilometer abraded volumes measurement.
Results showed that axes misalignment and sample slope involve considerable errors in wear coefficient evaluation. However, errors can be corrected by the use of obtained expressions. Copyright Β© 2009 John Wiley & Sons, Ltd.
π SIMILAR VOLUMES
Pb(Zr 0.53 Ti 0.47 )O 3 (PZT) thin films grown on Pt-coated Si substrates were prepared by a sol-gel process. Crystalline structure characterisation and optical constants (refractive index n, extinction coefficient k) and bandgaps E g of PZT thin films annealed at 550, 600 and 650 β’ C were obtained