3D surface roughness characteristics for biological applications

Titanium alloy is used in medical industries due to its biocompatibility. Requirement of implant’s surface roughness and surface topography depends mainly upon its application. In the present study, application of titanium alloy is considered as femoral knee joint implant. The capability of magnetic field assisted finishing (MFAF) process and the polishing tool to provide implant worthy surface is analyzed here. In MFAF process, magnetorheological fluid mixed with abrasive powder in acidic base medium is used as the finishing medium. Characterization of the finished surface is carried out by analyzing 3D surface roughness parameters. The selected 3D surface parameters ( Sa, Spk, Sk and Svk) are considered due to their importance concerning load-bearing articulating surface of knee joint implant. Statistical design of experiment is used for experimental study and subsequently process parameters are optimized. From experimental investigation, the values of Sa, Spk, Sk and Svk are obtained as 11.32 nm, 15.82 nm, 6.51 nm and 41.15 nm, respectively, at optimum process parameter condition. The optimum process parameter values are 901 rpm of the tool, 0.60-mm working gap and 4.30 hrs of finishing time. The obtained values of 3D surface roughness parameters are in the nanometer range and the surface topography will render better wear properties, performance and longer implant life. Further confirmation experiments support the optimized values. The effect of individual process parameter on output responses is also analyzed.

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EVALUATION OF SURFACE ROUGHNESS PRODUCED BY NANOCUTTING COPPER STRUCTURE USING A LEAST SQUARE MEAN METHOD

Surface Review and Letters ◽

10.1142/s0218625x19500811 ◽

2019 ◽

Vol 27 (01) ◽

pp. 1950081 ◽

Cited By ~ 1

Author(s):

CHUNHUI JI ◽

SHUANGQIU SUN ◽

BIN LIN ◽

TIANYI SUI

Keyword(s):

Surface Roughness ◽

Cutting Speed ◽

Least Square ◽

Depth Of Cut ◽

Real Surface ◽

Roughness Parameters ◽

Machined Surface ◽

Surface Roughness Parameters ◽

3D Surface ◽

3D Surface Roughness

This work performed molecular dynamic simulations to study the 2D profile and 3D surface topography in the nanometric cutting process. The least square mean method was used to model the evaluation criteria for the surface roughness at the nanometric scale. The result showed that the cutting speed was the most important factor influencing the spacing between the peaks, the sharpness of the peaks, and the randomness of the profile. The plastic deformation degree of the machined surface at the nanometric scale was significantly influenced by the cutting speed and depth of cut. The 2D and 3D surface roughness parameters exhibited a similar variation tendency, and the parameters Ra and Rq tended to increase gradually with an increase in the cutting speed and a decrease in the depth of cut. Finally, it is concluded that at the nanometric scale, the 3D surface roughness parameters could more accurately reflect the real surface characteristics than the 2D parameters.

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Theoretical Analysis of Spacing Parameters of Anisotropic 3D Surface Roughness

Latvian Journal of Physics and Technical Sciences ◽

10.1515/lpts-2017-0013 ◽

2017 ◽

Vol 54 (2) ◽

pp. 55-63 ◽

Cited By ~ 2

Author(s):

J. Rudzitis ◽

N. Bulaha ◽

J. Lungevics ◽

O. Linins ◽

K. Berzins

Keyword(s):

Surface Roughness ◽

Aspect Ratio ◽

Longitudinal Direction ◽

Anisotropy Coefficient ◽

Anisotropic Surface ◽

Measuring Devices ◽

3D Surface ◽

3D Surface Roughness ◽

The Mean ◽

Iso 25178

Abstract The authors of the research have analysed spacing parameters of anisotropic 3D surface roughness crosswise to machining (friction) traces RSm1 and lengthwise to machining (friction) traces RSm2. The main issue arises from the RSm2 values being limited by values of sampling length l in the measuring devices; however, on many occasions RSm2 values can exceed l values. Therefore, the mean spacing values of profile irregularities in the longitudinal direction in many cases are not reliable and they should be determined by another method. Theoretically, it is proved that anisotropic surface roughness anisotropy coefficient c=RSm1/RSm2 equals texture aspect ratio Str, which is determined by surface texture standard EN ISO 25178-2. This allows using parameter Str to determine mean spacing of profile irregularities and estimate roughness anisotropy.

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