Rentgenska praškovna difrakcija livarskih peskov.

Martinc, Nina (author), Meden, Anton (mentor)

Rentgenska praškovna difrakcija je metoda, ki temelji na difrakciji rentgenske svetlobe na kristaliničnih trdninah. Za kristalinične snovi je značilen red dolgega dosega. Ko rentgenski žarek trči ob kristal pride do pojava sipanja. Rezultat meritve so difraktogrami, s pomočjo katerih identificiramo snovi. Vsaka kristalinična faza ima edinstven praškovni difraktogram, kar omogoča kvalitativno analizo različnih trdnin. Glavni namen diplomskega dela je bila analiza livarskih peskov, ki so večinoma sestavljeni iz kristaliničnih snovi. V diplomskem delu sem analizirala 12 po sestavi in kompleksnosti različnih vzorcev peskov, ki se uporabljajo v livarskih procesih. Dobljene difraktograme sem obdelala in primerjala s pomočjo programa X'Pert HighScore Plus. S tem programom sem na podlagi enakih vrhov vzorce razporedila v skupine. Komponente v vzorcih sem nato identificirala s programom Crystallographica Search-Match, kjer sem difraktograme vzorcev primerjala s standardi v podatkovni zbirki PDF. Pri bolj kompleksnih vzorcih sem izvedla kvantitativno analizo s programom Topas, ki sem ga uporabila za Rietveldovo prilagajanje. Pri nekaterih vzorcih nisem uspela identificirati popolnoma vseh vrhov, saj so bile nekatere spojine prisotne v zelo majhnih količinah oziroma primeseh. Druga možnost, ki je razlog za neidentifikacijo je ta da so spojine amorfne in niso opazne na difraktogramih, povzročijo pa višje ozadje. Sestava livarskih peskov, ki sem jo določila, se je ujemala s podatki iz literature.

• Language: Slovenian
• Keywords: rentgenska praškovna difrakcija, livarski peski, livarstvo, kvalitativna in kvantitativna fazna analiza.
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2022
• PID: 20.500.12556/RUL-139055
• COBISS.SI-ID: 121690115
• Publication date in RUL: 29.08.2022

Secondary language

• Language: English
• Title: X-ray powder diffraction of foundry sands.

Abstract

X-ray powder diffraction is a method based on the diffraction of X-ray light by crystalline solids. Crystalline materials are characterised by long-range order. When an X-ray beam hits a crystal, scattering occurs. The result of the measurements are diffractograms, which are used to identify the substances. Each crystalline phase has a unique powder diffractogram that allows us to qualitatively analyse different fortresses. The main aim of the thesis was the analysis of foundry sands consisting mainly of crystalline materials. In my thesis, I analysed 12 different samples of sands used in foundry processes in terms of their composition and complexity. The diffractograms were processed and compared using X'Pert HighScore Plus. Using this programme, I grouped the samples based on equal peaks. The components in the samples were then identified using Crystallographica Search-Match, comparing the diffractograms of the samples to the standards in the PDF database. For more complex samples, I performed quantitative analysis with Topas, which I used for Rietveld fitting. For some samples, I was unable to fully identify all peaks because some compounds were present in insufficient amounts or as admixtures. The reason for the non-identification may also be that the compounds are amorphous and are not visible in the diffractograms, but cause a higher background. The composition of the foundry sands that were determined was consistent with the literature data.

• Keywords: X-ray powder diffraction, foundry sands, foundry, qualitative and quantitative phase analysis