Applicability of Interrupted Micro Cutting Process “Tilling” as Surface Texturing

Abstract

Tribological properties of textured surfaces fabricated using a discontinuous microcutting process were investigated. Aluminum cast alloy (AC8A) discs were used for the specimens. The texturing process was carried out using a CNC machining center with a cutting edge with a novel geometry. The resulting surface morphology consisted of micro dimples with a diameter of 200-300 μm and a depth of 5-10 μm, with controlled area fractions of 10 and 40% and a top region finished with a milling cut. The tribological properties were evaluated using a ring-on-disc type testing apparatus under lubricated conditions, and showed that the friction coefficient of the textured surfaces was low and stable from the beginning of the experiment. A dependence of the friction coefficient on the area fraction was also found. Further reductions in the friction coefficient were achieved on a textured surface with a polished top region. It can be concluded that the proposed discontinuous micro cutting process is an effective means of fabricating a micro texture for the reduction and stabilization of frictional resistance.

Running-in friction of hip joint replacements can be significantly reduced: The effect of surface-textured acetabular cup

“…In addition, the sleeves around the dimples occurring due to elevated temperature leading to increased wear are often observed. Therefore, so-called "tilling" technology, previously successfully applied when texturing aluminium alloy [15], was employed in the present study. The dimples were made by fixing the fabricated UHMWPE cup to a chuck of CNC machining centre.…”

Replication Study of Molded Micro-Textured Samples Made of Ultra-High Molecular Weight Polyethylene for Medical Applications

“…Moreover, in UHMWPE implants, osteolysis is infrequent when the wear rate is up to 0.1 mm/y, and it is almost absent when its value is 0.05 mm/y or below [ 1 ]. A wear rate of 0.1 mm/y will result in a CoF threshold of about 0.02, which can be achieved with hydrodynamic friction [ 10 ].…”

“…Usami H. et al [ 10 ] proposed surface micro-texturing on samples made of aluminum alloy for casting (AC8A-T6). Arrays of micro-dimples with diameters in the range ∅200–300 μm, depths of 5–10 μm, and area fractions of 10 and 40% were manufactured by micro-tilling (interrupted milling) on disk samples.…”

“…Hemispherical dimples allow higher tribological properties than other geometries (flat and conical). Surface micro-texturing results in a CoF reduction of about 25–27% under different load pressure conditions [ 10 ]. Dong Y. et al [ 12 ] studied the tribology of micro-texturing and low-temperature plasma carburizing on CoCrMo structural components sliding on UHMWPE interface components in a hip joint prosthesis.…”

“…These criteria result in a set of design specifications for the micro-textures that should exhibit [ 22 ]: a pattern of micro-cavities; a symmetrical design to avoid anisotropy; a cavity area fraction (AF) in the range 10–40%, where AF is defined as the ratio of the cavity area and pattern unit cell area [ 10 ]. …”