468 KB21 KB200020242014Babič, MatejGuid, NikolaKokol, PeterPanjan, Peterštevilka:2letnik:48str. 203-208ISSN:1580-2949COBISSID:78019329URN:URN:NBN:SI:doc-Q2IUR2IMenInštitut za kovinske materiale in tehnologijeMateriali in tehnologijefractal structurefraktalna strukturahardeningHurst exponentHurstov eksponentkaljenjelaserobdelava materialarobotA new method for estimating the Hurst exponent H for 3D objects| Nova metoda za ocenjevanje Hurstovega eksponenta H za 3D-objekte|Mathematics and computer science are very useful in many other sciences. We use a mathematical method, fractal geometry, in engineering, specifically in laser techniques. Characterization of the surface and the interfacial morphology of robot-laser-hardened material is crucial to understand its properties. The surface microstructure of robot-laser-hardened material is rough. We aimed to estimate its surface roughness using the Hurst parameter H, which is directly related to the fractal dimension. We researched how the parameters of the robot-laser cell impact on the surface roughness of the hardened specimen. The Hurst exponent is understood as the correlation between the random steps X1 and X2, which are followed by time for the time difference t. In our research we understood the Hurst exponent H to be the correlation between the random steps X1 and X2, which are followed by the space for the space difference d. We also have a space component. We made test patterns of a standard label on the point robot-laser-hardened materials of DIN standard GGG 60, GGG 60 L, GGG 70, GGG 70 L and 1.7225. We wanted to know how the temperature of point robot-laser hardening impacts on the surface roughness. We developed a new method to estimate the Hurst exponent H of a 3D-object. This method we use to calculate the fractal dimension of a 3D-object with the equation D = 3 - HMatematika in računalništvo sta zelo uporabni veji drugih vrst znanosti. Uporabili bomo matematično metodo - fraktalno geometrijo - v inženirstvu, natančneje, v laserski tehniki. Karakterizacija površine in morfologija robotsko lasersko kaljenih materialov ima ključni pomen za razumevanje lastnosti materialov. Površina robotsko lasersko kaljenega materiala je hrapava. To hrapavost pa bi radi ocenili s Hurstovim eksponentom H, ki ga dobimo direktno iz fraktalne geometrije, kot meritev hrapavosti površine. Raziskali smo, kako parameter robotske celice vpliva na hrapavost kaljenih vzorcev. Hurstov eksponent H razumemo kot korelacijo med korakoma X1 in X2, ki ga dobimo med časovno razliko t. V naši raziskavi razumemo Hurstov eksponent H kot relacijo med korakoma X1 in X2, ki ga dobimo med prostorsko komponento. Osredinili smo se na točkovno robotsko lasersko kaljenje vzorcev standardne oznake po DIN-standardu GGG 60, GGG 60 L, GGG 70, GGG 70 L in 1.7225. Želeli smo izvedeti, kako temperatura točkovnega robotskega laserskega kaljenja vpliva na hrapavost površine. Razvili smo novo metodo za ocenjevanje Hurstovega eksponenta H za 3D-objekte. To metodo smo uporabili za računanje fraktalne dimenzije 3D-objektov po formuli D = 3 - HTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije