Problems of Flaking in Strengthening Shaft Burnishing

Effect of slide burnishing on the corrosion resistance and surface roughness on high strength steels

“…For burnishing forces between 180 and 270 N, similar values of the roughness indicators were obtained to 150 N, but with higher energy consumption compared to the burnishing force of 150 N. Although for the burnishing forces of 300 and 450 N the roughness indicators are lower than the initial of steel sheet before burnishing, Figure 4(a)) shows that the plastic deformation produced by the burnishing force of 150 N caused a good smoothing of the profile asperities reducing roughness indicators (blue roughness profile), while a burnishing force of 300 N (red roughness profile) produced visible spherical-tip marks of the tool on the sheet surface due to the spherical tip penetration in the material surface, which caused the accumulation or stacking of material around the tool increasing the roughness indicators as compared to indicators at burnishing force of 150 N, showing a semicircular pattern of the marks formed. This effect is reported by Dzionk et al, 41 Silva-A ´lvarez et al, 13 Capilla-Gonza´lez et al, 30 and Cui et al 42 Although this effect probably starts for the subsequent optimum burnishing force (150 N), which is the burnishing force of 180 N, the visually well-defined stacking phenomenon is observed up to a burnishing force of 300 N (Figure 4(a)). Similar to DP-330Y, the minimum roughness indicators for TRIP-440Y material were obtained for a burnishing force of 180 N, even though lower values of roughness indicators are exhibited between 210 and 300 N (Figure 3), at 300 N of burnishing force are already evident tool marks (Figure 4(b)), undesirable in the surface finish due severe plastic deformation.…”

Experimental and Numerical Analysis of the Depth of the Strengthened Layer on Shafts Resulting from Roller Burnishing with Roller Braking Moment

“…Movement of the roller in relation to the material, which is a combination of burnishing speed and feed motion, causes most of the flowing material to accumulate in front of the tool. The creation of an additional material structure in front of the tool is noted in the literature and in workshop slang is referred to as the “jumping wave” [ 36 , 37 ] or “the wave of plastically deformed material” [ 22 ]. The equivalent plastic strain values in the zone of the “jumping wave” have much higher values (point B in Figure 21 a) than in the stable burnishing zone.…”