Experimental Evaluation of Oxide Nanoparticles as Friction and Wear Improvement Additives in Motor Oil

Table 1

Surface parameters of the samples used in this work.

	Liner	PVD CrN Ring
Surface arithmetic roughness (m)	0.468	0.288
Surface RMS roughness (m)	0.677	0.402
Skewness	−2.132	−0.762
Kurtosis	8.606	6.270
Maximum peak height (m)	2.247	5.290
Maximum valley depth (m)	−4.565	−3.223
Maximum height (m)	6.812	8.513