Otpornost na trošenje TiO2 sol-gel filmova

Primorac, Ivan (2014) Otpornost na trošenje TiO2 sol-gel filmova. = Wear resistance of TiO2 sol-gel films. Undergraduate thesis , Sveučilište u Zagrebu, Fakultet strojarstva i brodogradnje, UNSPECIFIED. Mentor: Grilec, Krešimir.

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Abstract (Croatian)

Sol-gel metoda kao relativno nova metoda u zadnjih nekoliko godina dobiva sve veću pažnju zbog niza prednosti poput niske temperature postupka, visoke homogenosti, mogućnosti stvaranja prevlake na velikim površinama te niskih investicijskih troškova. U ovom radu je opisan postupak nanošenja tankih nanostrukturiranih keramičkih prevlaka titan dioksida TiO2 na podloge od čelika X5 Cr\Ni 18-10 , sol-gel postupkom tehnikom uranjanja. Prije nanošenja prevlake pripremljene su čelične površine i sol. čelične površine su mehanički brušene brusnim papirima od silicijevog karbida SiC različitih granulacija i zatim polirane dijamantnom pastom. Za pripravu sola korišten je titanov izopropoksid kao prekursor, propanol kao otapalo, uz dodatak nitratne kiseline kao katalizatora te acetilacetona za peptizaciju. \Nakon priprave sola provedeno je nanošenje prevlaka postupkom uranjanja u sol. Dva uzorka su uranjana u sol brzinom 10 mm/min , a druga dva brzinom 100 mm/min, držani su u solu 3 minute kako bi se omogućilo kvašenje podloge. Brzina izranjanja bila je također 10 mm/min te 100 mm/min. \Nakon postupka uranjanja, čelični uzorci su sušeni na sobnoj temperaturi u trajanju od 1 sata te su nakon toga sušeni na temperaturi od 100 °C u trajanju od 1 sata. Postupak uranjanja i sušenja ponavljan je 3 puta sa ciljem povećanja debljine. \Nakon toga 2 uzorka su kalcinirana na temperaturi od 500 °C, a druga dva na temperaturi od 400 °C , oba u trajanju od 1 sata. \Nakon nanošenja nanostrukturiranih TiO2 keramičkih prevlaka ispitivana je otpornost na erozijsko trošenje navedenih prevlaka. Ispitivan je utjecaj oblika i tvrdoće zrna na erozijsko trošenje kao i utjecaj različitih kuteva upada čestica na gubitak mase prilikom ispitivanja. Ispitivanje otpornosti na erozijsko trošenje vršeno je pomoću kvarcnog pijeska SiO2 kao erodenta pri kutevima od 30° i 90° te sačme promjera 700μm pri kutu od 30°. Analiza mikrostrukture i sastava površine nakon erozijskog trošenja vršena je pomoću pretražnog elektronskog mikroskopa (SEM). Rezultati su pokazali da nepravilni oblik zrnaca kvarcnog pijeska uzrokuje više štete na površini nego sačma promjera 700μm te da manja brzina uranjanja i izranjanja uzorka ipak neće dati i deblji sloj te veći sadržaj titana u sloju.

Abstract

Sol-gel method as a relative new method have been receiving much attention in the past few years because of several advantages, such as low processing temperature, homogeneity, the possibility of coating on substrates with large areas, and low cost. In this study the deposition of TiO2 nanostructured, thin, ceramic coatings on steel grade X5 CrNi 18-10, by dip-coating technique is described. Before the deposition of films, steel substrates and gel-solution were prepared. Steel substrates were ground with SiC abrasive discs and then polished with diamond paste. For a preparation of sol titanium, isopropoxide was used as a precursor, propanol was used as a solvent with addition of nitric acid as a catalyst and acetylacetone for peptization. After preparation of sol, depositing of coatings by dip-coating technique was made. Two steel substrates were dipped into sol at a rate of 10 mm/min and two at a rate of 100 mm/min, then were held in solutions for 3 minutes, in order to allow surface wetting. The withdrawal speed was also 10 mm/min and 100 mm/min. After dip coating, the steel substrates were dried at room temperature for an hour and after that, each steel substrates was dried at 100 °C for an hour. The dipping process was repeated three times to increase the film thickness. After dip-coating and drying, two steel substrates were calcined at 500 °C for 1h and two were calcined at 400 °C for 1h. After the deposition of TiO2 nanostructured ceramic coatings, erosion wear behavior of TiO2 ceramic coating is studied. The influence of particle hardness and shape on erosion of TiO2 ceramic coating is examined. The effect of varying the impingement angle on the weight loss is also determined. Therefore, erosive wear behavior of TiO2 ceramic coating was investigated using SiC as erodent at impact angles of 30° and 90° and steel erodent particle of nominal 700m diameteras at impact angle of 30° . Scanning electron microscopy (SEM) was used to analyze the eroded surfaces in order to determine erosion mechanisms. The results indicate that hard, angular SiC particles cause more damage than steel erodent particle of nominal 700m diameter, and that lower dipping and withdrawal speed will not give thicker layer and higher content of titanium in the layer.

Item Type: Thesis (Undergraduate thesis)
Uncontrolled Keywords: TiO2 tanke prevlake; sol-gel; keramičke prevlake; erozijsko trošenje
Keywords (Croatian): TiO2 thin film, sol-gel , ceramic coatings, erosion wear
Divisions: 1000 Department of Materials > 1010 Chair of Materials and Tribology
Date Deposited: 22 Sep 2014 18:00
Last Modified: 16 Oct 2015 12:48
URI: http://repozitorij.fsb.hr/id/eprint/2665

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