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Aluminij zaradi svojih idealnih lastnosti imenujemo kovina moderne dobe. Za aluminijeve gnetne zlitine skupine 2xxx je značilna slabša odpornost proti koroziji in dobre trdnostne lastnosti. Baker, kot glavni legirni element, zagotavlja trdnost na širokem temperaturnem območju. Je zelo primerna za uporabo na avtomatskih stružnicah, kjer lahko izdelujemo kompleksne dele. Električna prevodnost je lastnost materiala, ki opiše njegovo zmožnost gibanja električno nabitih delcev. Nanjo vpliva temperatura, kristalna struktura oz. število prostih elektronov, mobilnost in s tem povprečna hitrost elektrona. Uporu, na katerega elektroni naletijo med gibanjem pa pravimo električna upornost. V diplomski nalogi zaznavamo mikrostrukturne spremembe aluminijeve zlitine EN AW 2011 med toplotno obdelavo s pomočjo štiri-točkovne metode, kjer se za merjenje upornosti vzorcev uporablja štiri-stopenjska sonda in enosmerni tokovni vir. Določili smo ne le temperaturna območja sprememb, temveč smo s SEM-EDS analizami, Thermo-Calc analizo in DSC analizo tudi prišli do sklepov o dogajanju v temperaturnih območjih. Aluminium is called the metal of the modern age because of its ideal properties. 2xxx series aluminium wrought alloys are characterized by poorer corrosion resistance and good strength properties. Copper, as the main alloying element, provides strength over a wide temperature range. It is very suitable for use on automatic lathes, where complex and detailed parts can be produced. Electrical conductivity is a property of a material that describes its ability to move electrically charged particles. It is influenced by temperature, crystal structure or number of free electrons, mobility and thus the average velocity of the electron. The resistance that electrons encounter during motion is called electrical resistance. In the diploma thesis we detected microstructural changes of aluminium alloy EN AW 2011 during heat treatment using a four-point method, where a four-stage probe and a direct current source are used to measure the resistance of the samples. We determined not only the temperature ranges of changes, but with SEM-EDS analysis, Thermo-Calc analysis and DSC analysis we came to conclusions about what is happening in the temperature ranges. |
