Sinteza i karakterizacija prahova sulfida kalaja i volframa za primenu u tribološkim materijalima

Abstract

U doktorskoj disertaciji su prikazani postupci sinteze prahova sulfida kalaja i volframa za primenu u tribološkim materijalima određivanjem optimalnih parametara procesa sinteze na osnovu rezultata termodinamičkog modelovanja primenom softverskog paketa HSC Chemistry® verzija 9.9.2.3. Upotreba termodinamičkog predviđanja u optimizaciji procesa sinteze je primenjena u cilju dobijanja unapređenog načina sinteze sulfida kalaja i volframa sa tehnološki optimalnim brojem operacija, što doprinosi pojednostavljenju postupka i uštedi energije. Proces sinteze je dodatno optimizovan variranjem količine i sastava polaznih materijala, kao i osnovnih procesnih parametara (temperatura i trajanje procesa sinteze). Takođe je izvršen odabir adekvatnog aditiva radi povećanja efikasnosti procesa sinteze, čiji je pozitivan uticaj potvrđen eksperimentalnim rezultatima. Pored toga, proces sinteze sufida kalaja je okarakterisan metodom termičke analize, simultanom diferencijalnom skenirajućom kalorimetrijom i termogravimetrijskom analizom (DSC – TGA). U okviru doktorske disertacije za potrebe sinteze sulfida volframa izvršena je i sinteza oksidnog prekursora metodom ultrazvučnog sprej raspršivanja. Nakon procesa sinteze izvršena je karakterizacija sintetisanih prahova različitim instrumentalnim metodama. Karakterizacija sintetisanih prahova je obuhvatila analizu hemijskog sastava optičkom emisionom spektroskopijom sa indukovano spregnutom plazmom (ICP - OES), određivanje faznog sastava i stepena kristalizacije rendgenskom difrakcionom analizom (XRD) sa Rietveldovom metodom pomoću Powder Cell i RIFRANE® programa, ispitivanje morfologije kao i elementalnog sastava skenirajućom elektronskom mikroskopijom sa energodisperzionom analizom (SEM - EDS). Ova doktorska disertacija je urađena u okviru realizacije projekta tehnološkog razvoja koje je finansiralo Ministarstvo prosvete, nauke i tehnološkog razvoja Republike Srbije, evidencioni broj 34033 ”Inovativna sinergija nus-produkata, minimizacije otpada i čistije proizvodnje u metalurgiji” (2011-u toku).

This PhD thesis presents the process of synthesis of tin and tungsten sulfides powders for application in tribological materials by determining the optimal parameters of the synthesis process based on the results of the thermodynamic modeling. The thermodynamic modeling of the synthesis process was determined using HSC Chemistry® software modelling package, version 9.9.2.3. The thermodynamic modeling was applied in order to obtain an improved method of tin and tungsten sulfides synthesis with a technologically optimal number of operations, which contributes to the simplification of the process and energy savings. Further optimization of the synthesis process was done by varying quantity and composition of the starting materials for synthesis, as well as the basic process parameters (temperature, duration of the process of synthesis). The selection of adequate additives for process efficiency increase was also investigated. In addition, the synthesis process of tin sulfides was also characterized by the thermal analysis method, simultaneous differential scanning calorimetry and thermogravimetry (DSC-TGA). As a part of this doctoral dissertation, the synthesis of oxide precursor for tungsten sulfide synthesis was carried out by using the ultrasonic spray pyrolisis method. After the synthesis process, the characterization of powders with different instrumental methods was performed. The characterization of the synthesized powders included analysis of chemical composition by inductively coupled plasma optical emission spectroscopy (ICP - OES), phase composition identification and degree of crystallinity were analysed by X-ray diffraction (XRD) by employing the Rietveld method with the help of PowderCell Software and the RIFRANE® program and examination of morphology, as well as elemental composition by scanning electron microscopy with energy-dispersive spectroscopy (SEM - EDS). This PhD thesis is part of the technological development project funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia, No. 34033 ”Innovative synergy of by-products, waste minimization and clean technologies in metallurgy” (2011-in progress).