The machining of magnesium alloys has gained a considerable interest in recent years, leading to numerous studies on machining processes such as milling, turning, AWJ cutting, and brushing. One interesting yet inadequately studied machining technique is that combining two machining methods: dry end milling (as a pretreatment) and ball burnishing (as a treatment for shaping beneficial properties of the surface layer). Therefore, this study investigates the impact of variable feed in dry end milling and that of ball burnishing force. The following qualitative indicators are analyzed: surface topography, surface roughness parameters (Sa, Sz, Ssk, Sku, Smr), material bearing curve (Abbott-Firestone curve), and selected profilograms. Results show that the combination of these two machining methods can have a beneficial effect on the stereometric properties of the surface layer, revealing the mechanism of so-called surface topography rebuilding after ball burnishing. Following an increase in the burnishing force, the milled surface is deformed to a greater extent, the Ssk parameter takes negative values, while the Sku parameter has positive values of >3. This surface exhibits characteristic features, including improved contact conditions in the friction pair. Moreover, owing to such operating parameters, this surface can become a “trap” for capturing wear particles. The Abbott-Firestone curve for milled samples has a degressive-progressive pattern, regardless of the applied feed. On the other hand, the profilograms show that the surface subjected to milling as a pretreatment exhibits a uniform distribution of micro-irregularities, whatever the feed.
Skoczylas et al. (Wed,) studied this question.