SU1714473A1 - Method for determining reflective capability of surface - Google Patents

Description

The invention relates to a measurement technique, more precisely to the measurement of the tBnTwme characteristics of materials, and can be used to determine the reflective ability of polished MetaAlic. | 1 superstructures of complex configuration.

lieJTib invention - increased accuracy. ; -. . , : -: -. -The method is carried out as follows .3 ..:. -, , , ; : -; .. hoBepxtidCTb details scan the device with an indenter of a sclerometer. The magnitude of the tangeyzzal: noe composition | is measured (the apparent force of the resistance of the surface layer of the material during contact deformation along the tracks

scan. The frequency distribution of the probability density of the deviation of this magnitude from the average value is determined. According to the obtained frequency distribution, the frequency dividing this distribution into two equally-sized regions is determined, and the reflectivity of the material is judged by the calibration dependence. Fig. 1 shows the dependence of the tangential component of the resistance force of the surface layer of stainless steel on various strengths and sizes of crystallites along the path, and scanning; Fig. 2 - the corresponding frequency distribution of the probability density of the tangential component deviation | the resistance of the surface layer of the average value of 6m along the scan path; in fig. 3 - dependence of the tangential component of the resistance of the surface layer of stainless steel on the size of the crystallites along the scan path; in fig. 4 shows the corresponding frequency distribution of the probability density of the deviation of the tangential component of the resistance of this supersport layer from the average value along the scan path; in fig. 5 frequency distributions of the probability density of the tangential component of the resistance of the surface layers of polished stainless steel specimens with different reflectivity of optical radiation. As measured samples, samples of hot rolled 12X18H10T steel were taken after treatment with abrasive tapes. To eliminate the effect of surface microgeometry on the amount of specular reflection, the surfaces of samples of the same roughness are compared. The different state of the surface layer is obtained by varying the conditions of belt grinding. Treatment conditions and characteristics of the treated surface are presented in the table. The values of the specular reflection coefficients of these samples given in the table are determined by the photoelectric gloss meter FB-2 in comparison with the specular reflection coefficient of a household mirror according to GOST 17716-82, the value of which is taken as 100%. The surfaces of the samples are scanned by an indenter loaded with a force of 3.5N at a speed of ..5 μm / s. When scanning the sample surface with a loaded indenter, depending on the size and strength of the crystallites, the tangential component of the resistance force of the surface layer to contact deformation (Fig. 1) changes, the frequency distribution of the probability density of the deviation from the mean value of which contains the information o, the structure of the surface layer, the effective size of R. fragments. .r ,,, .- aM which is determined by the formula c, where f is the frequency of the bursts. Bursts of the value of the tangential component of the resistance force occur either on low hardness crystallites or between crystallites. The magnitude of reflectivity is related to the size of solid crystallites on the surface, the predominance of which is characterized by a decrease in the frequency of bursts of the tangential component of the resistance force (Fig. 3} and a shift in the frequency distribution of the probability density of the deviation of this force from the average value along the scanning path to the low frequencies (Fig. 4) Thus, the internal state of the surface layer is determined by the resistance of local areas to contact deformation when scanning with diamond The detector on the device for sclerometric studies of materials. When tested using these tools, the friction strength of the diamond indenter is modulated with the frequency of fragments, characterized by amplitudes of similar magnitude due to strength changes at the boundary and within local regions. In general, the Mathematical description of the structural state of the surface layer is given by an aggregate following main characteristics., The mathematical expectation of the input (output) signal jx (t) dt, t6T, where x (t) is the input (output) signal. al; T observation time interval. Mathematical; the expectation evaluates the static, time independent component of the input (output) signal. Dispersion of the input (output) signal Dx lim (Dispersion estimates the dynamic component of the input (output) signal as its average power of oscillations relative to the static component. The correlation function of the input (output) signal Rx (t, -i J x (t ) -inxIx (, T- I where T, r is the time increment. The correlation function evaluates the relationship of the values of the input (output) signal at different points in time with the rate of its change.

The frequency distribution of the probability density of the input (output) signal deviation from the average value, i.e. spectral density of the input (output) signal

+ -2WJfTdT

Sx (f) J Rx (t, U) e

, - 00 ....

.

This characteristic gives an idea of the harmonic composition of the signal, the distribution of the dispersion in frequencies and allows us to estimate the fraction of large and solid crystallites of the Hd surface from the shift of the frequency distribution in the frequency range.

Offset of the frequency distribution of the probability density of the signal deviation from the average value for various samples is conveniently characterized by the frequency fcp. separating the corresponding distribution into two equal areas; This frequency is determined from the ratio

fcp-boo

J Sx (f) df / Sx (f) df,

ofcp

as the abscissa, the section of the SSCH and limited schedule-Sxff) m axis 01 figure into two equal parts of the area.

 The reflectivity of the material surface under study is determined by the pre-constructed calibration dependence on fcp for samples with different surface uniformity and known reflectivity.

The plots (Fig. 5) show the frequency distributions of the probability density of the tangential component of the resistance force of the surface layer of the samples shown in the table, with contact deformation from the mean banner along the scan path.

The curves in FIG. 5 and the data in the table show that the mirror is the lowest

The reflectivity of 14% corresponds to the surface layer of a heterogeneous structure with the presence of large and small fragments at frequencies of 0.20; 0.30: 0; 60 and 0.75 Hz (curve 1).

A more uniform surface layer with predominant fragmentation at a frequency of 0.25 Hz has a higher specular reflectance of 18% (curve 2). Mirror reflection itself is high

35% was obtained on the surface with a uniformly strained large-fragment structure of the surface layer of fragmentation at frequencies of 0-0.75 Hz (curve 3). The corresponding frequencies for these plots

the fcp separating the vibration spectra into two equiparate domains have a value of 0.39; 0.27 and 0.2 Hz. The correlation coefficients between fcp and the specular reflectance are in the range of-0.8 to-0.78.

The method makes it possible to determine the reflectivity of the surface of metal parts of a complex configuration without access of optical devices with an error of about 10%.

Forms of the street and 3 turn and Method of determining the reflectivity of the surface of materials, which consists in the fact that the surface

scan, measure the surface characteristic along the scan path, and judge the magnitude of the reflectivity of the surface of the material using the measurement results;

In order to improve accuracy, the surface is scanned by an indenter and the tangential component of the resistance force of the surface layer is measured during contact deformation, the

The frequency distribution of the probability density of the deviation of this magnitude from the average value along the scan path, determines the frequency dividing this distribution into two equally-sized regions, and determines the reflectance of the surface of the material from the calibration curve.

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Claims (1)

Claim The method for determining the reflectivity of the surface of materials, which consists in the fact that the surface is scanned, the characteristic of the surface is measured along the scanning path, and the measurement results judge the magnitude of the reflectivity of the surface of the material, such as In order to improve accuracy, the surface is scanned by the indenter and the tangential component of the resistance force of the surface layer is measured during contact deformation, the frequency distribution of the density The deviations of this value from the average value along the scan path determine the frequency dividing this distribution into two equally probable regions, and the reflectivity of the surface of the material is judged by the calibration curve. 1714473 8 Features ob- | worked on top! J bh * nh 8 δ * "o m HG SO SH t-t-SP Roughness, P About Ra, microns Joint venture midrange cm cm midrange cm o o o ' 1 Belt grinding conditions sozh Emulsion i 1 in to to! K O) tM. LLC C © <0 <0 The speed of movement of the sample, m / min tn in to Speed. Tapes, m / s t- · |> t <cm 'cm' cm 'cm cm cm Machine time, min oh oh to soo see Clamping Force 1 N / cm SO SO G * “SCH Sizes, mm processed sample OOO g- gcm see cm 6 about about CD with the joint venture X XX yes with to [tapes 65x1900 65x1900 65x1900 Tape characteristic c'fct yes tn tn I cm cm CM <OO '4 · "T4 in tn Sample CM cn Compiled by S. Chuklyaev Editor O. Yurkovetskaya Tehred M. Morgenthal Corrector T. Malets Order 688 Circulation Subscription VNIIIPI of the State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.