magistrsko delo magistrskega študijskega programa II. stopnje Strojništvo
Blaž Kusterle (Author), Mitjan Kalin (Mentor)

Abstract

Realna kontaktna površina je v tribologiji ključnega pomena, saj igra veliko vlogo pri obnašanju kontaktov med površinami. Med njihovim konstruiranjem moramo natančno analizirati realno kontaktno površino in interakcije na njej, saj vplivajo na številne lastnosti kontakta, kot so temperatura, tlak, obraba, ter električna in toplotna prevodnost. Vse te lastnosti so pri kontaktu zelo pomembne, saj imajo velik vpliv na njegovo delovanje in posledično tudi na njegovo življenjsko dobo. V delu smo površine vzorcev dveh različnih jekel in treh različnih hrapavosti obremenjevali do meje tečenja materiala ob safirno steklo, sproti pa zajemali sliko kontakta, da smo lahko opazovali dogajanje na kontaktni površini. Slike smo spremenili v binarno obliko in jih s programsko kodo analizirali. Površino pred in po obremenjevanju smo zajeli še z interferometrom. Realna kontaktna površina se med obremenjevanjem skoraj enakomerno povečuje, število vršičkov pa v prvi polovici obremenjevanja narašča, nato pa začne padati. Trdota jekla na njo ni imela vpliva, medtem ko se z večanjem hrapavosti razmerje med realno in nominalno kontaktno površino zmanjšuje. Pri hrapavosti Ra = 0,1 µm znaša do 24 %, pri hrapavosti Ra = 0,3 µm do 19 %, pri hrapavosti Ra = 1 µm pa do 9 %.

Keywords

magistrske naloge;realna kontaktna površina;interakcije med vršički;in-situ meritve;hrapavost površine;trdota površine;obdelava slik;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FS - Faculty of Mechanical Engineering
Publisher: [B. Kusterle]
UDC: 539.92:669.1:004.932(043.2)
COBISS: 241119747 Link will open in a new window
Views: 100
Downloads: 26
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Other data

Secondary language: English
Secondary title: Asperity interactions on a real contact area
Secondary abstract: The real contact area is crucial in tribology, as it plays a significant role in the behavior of contacts between surfaces. During their design, we must carefully analyze the real contact area and interactions on it, as they influence various contact characteristics such as temperature, pressure, wear, as well as electrical and thermal conductivity. All these characteristics are essential for contact performance and affect its lifespan. In this study, the surfaces of specimens made of two different steels with three different roughness levels were loaded up to the yield strength of the material against sapphire glass, while capturing images of the contact in real-time to observe changes on the contact surface. The images were converted into binary format and analyzed using a custom software code. Additionally, the surface before and after loading was examined using an interferometer. The real contact area increases almost uniformly during loading, while the number of asperities initially rises in the first half of the loading process but then starts to decline. The hardness of the steel did not affect the contact area, whereas increasing roughness reduced the ratio between the real and nominal contact area. For a roughness of Ra = 0.1 µm the ratio is up to 24 %, for Ra = 0.3 µm up to 19 % and for Ra = 1 µm up to 9 %.
Secondary keywords: master thesis;real contact area;asperity interactions;in-situ measurements;surface roughness;surface hardness;picture processing;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. Ljubljana, Fak. za strojništvo
Pages: XX, 57 str.
ID: 26712191