Experimental Investigation of Tribology-Related Topography Parameters of Hard-Turned and Ground 16MnCr5 Surfaces

Abstract

Several surface topography parameters are available for the quantification of tribological properties of machined surfaces. Although these parameters and their influences are widely studied, there are contradictory findings due to the nature of the topography parameters, i.e., the behavior of different materials and cutting tool interactions lead to relatively varying numerical results. A comprehensive study of these interactions can contribute to more exact industrial machining applications. In this study, tribology-related 3D topography parameters of hard-machined (hard-turned and ground) surfaces were analyzed. The machining experiments were carried out based on a detailed design of the experiment; the analyzed material was case-hardened low-carbon content steel, which is widely used for automotive, industrial components such as bearings or gears. From the topography data, response function, correlation, and relative deviation analyses were carried out for the analyzed topography parameters, and tribology maps were created to support the selection of optimal cutting parameter values.

Influence of Ultrasound on the Characteristics of CaP Coatings Generated Via the Micro-arc Oxidation Process in Relation to Biomedical Engineering

“…71 , 72 On the other hand, when improving the surface homogeneity for samples from groups 136_450 and 136_600, when sinusoidal ultrasounds were used, which reached their maximum amplitude only in single moments, the main factor affecting the surface texture was the high current density. 74 The highest value for isotropy for the sample after modification was found for sample 68_450_rec (94.76 ± 0.92%), whereas the lowest value (86.15 ± 6.21%) is associated with sample 136_450_sin. As the samples were prepared equivalently, the effect of the process on the isotropy of the surface can be observed.…”

“…The use of bipolar rectangular ultrasound during the process in each case improved the isotropy, while sinusoidal ultrasound improved the isotropy only when the process was conducted with usage of a current of 136 mA and a time of 600 s. This phenomenon may be related to the previously mentioned ultrasound characteristics. The maximum amplitude ultrasound affects electrolyte fluctuations more and accelerates the MAO process’s kinetics, significantly contributing to surface formation. , On the other hand, when improving the surface homogeneity for samples from groups 136_450 and 136_600, when sinusoidal ultrasounds were used, which reached their maximum amplitude only in single moments, the main factor affecting the surface texture was the high current density . The highest value for isotropy for the sample after modification was found for sample 68_450_rec (94.76 ± 0.92%), whereas the lowest value (86.15 ± 6.21%) is associated with sample 136_450_sin.…”

“…Functional parameters from the Sk group facilitate analyzing the tribological properties of materials. , Thus, the following functional parameters of all samples were assessed: core height, reduced peak height, reduced valley depth, and areal material ratios of the scale-limited surface. The results are listed in Table .…”

“…The highest values of these parameters were obtained for sample 68_450_rec and the lowest values for sample 68_600_n. Generally, a relatively low Spk value indicates favorable wear resistance and a high Svk value designates beneficial lubricant retention ability, thereby creating a site suitable for cell proliferation. , For biomaterials, it is also essential to know what fraction of the coating would be “worn away” during work in the human body and what would probably remain. Due to this, the authors determined the Spk/coatings thickness (Spk/d) ratio, which could be used as an indicator of the durability of the coating.…”

Experimental Analysis of Effect of Machined Material on Cutting Forces during Drilling

“…The examination of thrust force and torque remains a key issue in drilling processes [ 48 ]. Experiments devoted to the machining of the material 16MnCr5 (case-hardened steel) were carried out by Molnar [ 49 ] in order to achieve the selection of the most favorable cutting parameters based on the DOE, correlation analysis, and relative deviation analysis. The study [ 50 ] examined the fretting and plain fatigue behavior of case-hardened steel 16MnCr5, which is comparable to AISI 5115, as reported in [ 51 ].…”