Asymmetric Height Distribution of Surfaces Machined by Hard Turning and Grinding

Abstract

The asymmetric height distribution of a machined surface can be useful from a tribological point of view in several cases. The purpose of this study is to analyze this asymmetry based on the 3D surface texture parameter skewness, providing technological parameter values that help in achieving favorable surfaces. A 16MnCr5 case-hardened steel (62–63 HRC) was machined by hard turning and grinding based on a comprehensive design of experiments and the topography of the surfaces was measured and analyzed. The texture parameter that informs about the height distribution of the surface points (skewness, Ssk) was compared to the volume parameters peak material volume (Vmp) and valley void volume (Vvv). The main finding is that negative Ssk values are found at low Vmp and Vvv values, which confirms the favorable tribological properties.

Evaluation of the Feasibility of the Prediction of the Surface Morphologiesof AWJ-Milled Pockets by Statistical Methods Based on Multiple Roughness Indicators

“…As several works have focused on Gaussian random surfaces, e.g., adopting the normal distribution for the description of height distribution for the machined surfaces, one of the tested distributions will be the normal distribution. However, the research will also include other distributions which could potentially model the height distribution, such as the Rayleigh, gamma, asymmetric generalized normal and skew normal distributions, as well as the Weibull distribution, which is more versatile than the others and can be more directly regulated to reproduce different types of rough surfaces which are usually non-Gaussian in the case of machined profiles [45]. Thus, motivated by the lack of studies related to surface roughness modeling based on multiple roughness indicators and the lack of realistic descriptions of rough surfaces, occurring after non-conventional machining or similar treatments, the objectives of this work are the following:…”

Preliminary Study On the Function-Defining 3D Surface Roughness Parameters in Tangential Turning

“…Therefore, these two parameters tell a lot about the functional behavior of the machined surface. The characteristic of Skewness and Kurtosis can be manipulated by the alteration of machining procedures [17] In hard turning, a negative Skewness was obtained only when the machining was carried out at relatively low feed rate [18], however it is usually not influenced by the depth-of-cut and the cutting speed. The Skewness and Kurtosis can be analyzed together on a so-called topological map [19], where the different machining procedures can be distinguished [20].…”