Non-contact method for surface roughness measurement after machining

Abstract

The paper deals with the measurement and identification of surfaces after machining in a non-contact manner. It presents a new modified measurement method and its implementation, the results of intensity distribution in the defocusing plane, their analysis and interpretation. The scanned intensity distribution at the defocusing plane gives information necessary to assess the second derivatives, and thus, surface functions which can be used to determine groove curvatures of the real surface morphology. The proposed method of measurement has proved to be very sensitive in evaluating the differences between surface finishing methods by which the measured surface standards (etalons) were machined. Two methods of machining were chosen: face grinding and planning. By comparing the roughness standard values Ra, there were obtained relationships between these values and the parameter of the characteristic frequency of vertical inequality being measured according to the presented method. A good correlation between the measured and surface standard values with the correlation coefficient taking a range of values from 0.8 to 1 was achieved.

Investigation of porous coatings obtained on Ti-Nb-Zr-Sn alloy biomaterial by plasma electrolytic oxidation: characterisation and modelling

“…The tracing, evaluation and single measuring lengths equal to 4.8, 4.0 and 0.8 mm, respectively. Due to the porous surface, the non-contact methods for surface roughness [47] were not possible to be used, inter alia because of the uncertainties in measurement results [48]. According to the EN ISO 4287:1999 [49] and DIN 4768 [50] standards, the following roughness parameters have been measured: arithmetic mean of the sum of roughness profile values (Ra), mean peak-tovalley height (Rz DIN ), ten-point height (Rz ISO ), root- mean-square deviation of the roughness profile (Rq), total height of the roughness profile (Rt), mean width of the roughness profile elements (RSm), the ratio of the developed profile length to the evaluation length (L 0 ) and profile peak density (D).…”

SEM and EDS Characterization of Porous Coatings Obtained On Titaniumby Plasma Electrolytic Oxidation in Electrolyte Containing Concentrated Phosphoric Acid with Zinc Nitrate

“…The tracing, evaluation and single measuring lengths, equal to 4.8, 4.0 and 0.8 mm, respectively, were used. Due to the porous surface, the non-contact methods for surface roughness [57] were not possible to be used, inter alia because of the uncertainties in measurement results [58]. According to the EN ISO 4287:1999 [59] and DIN 4768 [60] standards, the following roughness parameters have been measured: arithmetic mean of the sum of roughness profile values (Ra), mean peak-to-valley height (Rz DIN ), ten-point height (Rz ISO ), mean-square deviation of the roughness profile (Rq), total height of the roughness profile (Rt), mean width of the roughness profile elements (RSm), the ratio (l 0 =L/L 0 ) of the developed profile length (L) to the evaluation length (L 0 ) and profile peak density (D).…”

Development of copper-enriched porous coatings on ternary Ti-Nb-Zr alloy by plasma electrolytic oxidation

“…The tracing, evaluation, and single measuring lengths were equal to 4.8, 4.0, and 0.8 mm, respectively. Due to the porous surface, non-contact methods for surface roughness [81] were not possible to be used, inter alia, because of the uncertainties in measurement results [82]. According to the EN ISO 4287:1999 [83] and DIN 4768 [84] standards, the following roughness parameters have been measured: arithmetic mean of the sum of roughness profile values (Ra), mean peak-to-valley height (Rz DIN ), root mean square deviation of the roughness profile (Rq), total height of the roughness profile (Rt), the ratio of the developed profile length to the evaluation length (L 0 ), and profile peak density (D).…”