Determination of 3D Surface Roughness Parameters by Cross-Section Method

Autor: Janis Rudzitis, Armands Leitans, Juris Krizbergs, Māris Kumermanis, A. Ancans, N. Mozga
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Latvian Journal of Physics and Technical Sciences, Vol 51, Iss 2, Pp 60-64 (2014)
ISSN: 0868-8257
Popis: Currently in production engineering surface roughness parameters are evaluated in three-dimensions, however, equipment for these measurements is rather expensive and not always available. Furthermore, in many cases purchase of such 3D measurement equipment is not economically justified. Taking into account the above mentioned arguments, it is often needed to determinate 3D surface roughness parameters from the well know profile parameters (2D), by using common existing 2D surface roughness measurement equipment. The best solution for this is determination of 3D roughness parameters by using cross-section (or profile) method. This method shows good results in assessment of nanoroughness. Thus the following mean values of the microtopographical surface parameters can be calculated: roughness height; spacing parameters and form. Although this method is mainly applicable for the rough surfaces with the irregular character, it can be used for other types of rough surfaces too. Paper will cover overall methodological approach for the 3D surface roughness parameters, their calculations using surface cross-sections (cuts). Particular emphasis will be given to the correlations between the surface crosssection (profile) parameters and 3D parameters, as well as quantity choice of crosscuttings and their orientation on the surface will be done. The first step will be choice the input data, which should ensure sufficient information sources for the determination of the roughness height, spatial and form parameters. In this case is necessary to know the linear function h(x,y) and matrix of the correlation momentum. The second step will be to analyse the 3D surface roughness parameters correlation with profile parameters, by using the above mentioned correlation momentum matrix. Geometrical orientation of cross-sections will be evaluated as well as preferable angles and disposition of these cross-sections. Proceedings of the euspen International Conference – San Sebastian June 2009 1 Input data All information included in the input data must be minimal per size, but at the same time enough for determining height, step and form parameters. In that case it is necessary to know the two argument function h(x,y) [1], describing micro roughness as three dimensional object, its first and second derivations. Let’s denote: , ) , ( 1 y x h h = x y x x h ∂ ∂ = ) , ( 2 , y y x h h ∂ ∂ = ) , ( 3 , (1) 2 2 4 ) , ( x y x h h ∂ ∂ = , y x y x h h ∂ ∂ ∂ = ) , ( 2 5 , 2 2 6 ) , ( y y x h h ∂ ∂ = . For example, quantity h1 is used for determining roughness height parameters, h2 and h3 for surface gradient assessment, h4 and h6 – peak roundup. Prior to research all microtopographical parameters, based on quantities h1, h2, ..., h6, we must know six-rank density and they mutual distribution, defined by matrix: 66 56 55 46 45 44 36 35 34 33 26 25 24 23 22 16 15 14 13 12 11 k k k k k k k k k k k k k k k k k k k k k
Databáze: OpenAIRE
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