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Investigation of age-hardening of alloy systems Au-Ag-Cu for jewelry production

dc.contributor.advisorGusković, Dragoslav
dc.contributor.otherMarković, Desimir
dc.contributor.otherIvanov, Svetlana
dc.contributor.otherStojadinović, Slobodan
dc.contributor.otherJovančićević, Branimir
dc.creatorPerić, Radiša S.
dc.date.accessioned2016-07-23T16:13:25Z
dc.date.available2016-07-23T16:13:25Z
dc.date.available2020-07-03T09:17:10Z
dc.date.issued2014-10-10
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=3335
dc.identifier.urihttp://nardus.mpn.gov.rs/handle/123456789/5987
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:11803/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=47578639
dc.description.abstractProizvesti nakit od komada čistog zlata, iziskuje znanja iz različitih oblasti nauke, počev od metalurgije, fizičke hemije, mašinstva, preko medicine, pa do nauke o dizajnu i estetskim zahtevima, pri tome uvek uključujući i istoriju umetnosti. Sa stanovišta metalurgije, u disertaciji su razmotreni i eksperimentalno istraženi neki od veoma značajnih, ali nedovoljno izučenih aspekata, vezanih za pojedine faze proizvodnje nakita od legura na bazi zlata i srebra. Predmet ovog rada usmeren je na izučavanje, definisanje i optimizaciju najznačajnijih uticajnih parametara na finalna svojstva i kvalitet višekomponentnih legura sistema Au- Ag-Cu, u okviru istraživanja relacije: hemijski sastav – termička obrada – mikrostruktura – tvrdoća – električna provodljivost. Sve ovo zahteva multidisciplinaran pristup problemima proizvodnje nakita, posebno što nakit ispunjava potrebe čoveka za lepim. Proučavane su tri grupe legura, shodno zakonskoj regulativi u Republici Srbiji, i potrebama tržišta. Legura ,,žute“ boje je Au585Ag90Cu264Zn61, legura ,,bele“ boje je Au585Ag65Cu277Zn16Pd57, kao i legura srebra Ag925Cu75. Dodatno legiranje osnovnog trojnog Au-Ag-Cu sistema, urađeno je u cilju poboljšanja fizičko – mehaničkih osobina, kao što su čvrstoća legure, obradivost, sposobnost legure za razne oblike plastične deformacije, sposobnost za lemljenje i zavarivanje, itd. Kako u raznim stadijumima proizvodnje nakita, posebno u toku termičke i/ili mehaničke obrade dolazi do značajnih i višestrukih strukturnih promena, koje utiču i na boju materijala, a koje još uvek nisu dovoljno istražene, deo istraživačke pažnje posvećen je i usklađivanju istraživanih procesnih parametara sa očekivanom bojom ispitivanih legura. Posebna pažnja, u eksperimentalnom delu rada, usmerena je na istraživanje režima termičke obrade u procesu starenja, na temperaturama koje su niže od temperature rekristalizacije, u cilju utvrđivanja uticaja temperature i vremena, u odabranom ispitnom intervalu, na mikrostrukturu i fazne promene, koje su u direktnoj vezi sa ojačavanjem istraživanih sistema legura. Pojava strukturnih promena u kristalnoj rešetki legura, na granici faznih promena u čvrstom stanju (α(Au,Ag,Cu)↔α`(Ag,Au) + α“(Cu,Au)), fenomen ,,uređeno-neuređeno“ (formiranje uređenih rešetki: AuCuI, AuCuII, Au3Cu i AuCu3), pojava dvojnika žarenja, kao i drugih mikrostrukturnih promena, dovodi do toga da se značajno poveća čvrstoća u ovim legurama. Pored navedenih promena, takođe dolazi i do povećanja tvrdoće žarenjem na temperaturi starenja, usled pojave precipitacije, kako po granicama zrna, tako i u samom zrnu, zajedno sa nagomilavanjem i kočenjem dislokacija, koje su nastale hladnom deformacijom, i koje pokušavaju da se oslobode, dovođenjem spoljne energije. Ojačavanje istraživanih legura u procesu starenja praćeno je sistematskim ispitivanjem promene vrednosti tvrdoće, u odnosu na početno stanje, kao i na stanje nakon izvršene rekristalizacije...sr
dc.description.abstractIt takes knowledge of different parts of science to produce jewelery out of one piece of pure gold, starting from metallurgy, physical chemistry, mechanical engineering, through medicine, all to science of design and esthetical demands, always including the history of art. From the point of view of metallurgy, in this paper some of very important, but not enough examined aspects, that are connected to single phases of production of jewelry of gold and silver alloys, were considered and experimentally investigated. The subject of this paper was directed to research, define and optimization of the most important parameters that inflect on final properties and quality of multicomponent aloys of Au-Ag-Cu system, in terms of investigation of relation: chemical composition – thermal – processing – hardness – electrical conductivity. All of this demands multidisciplinary approach to the problem of production of jewelry, especially, because the jewelry fulfills the needs of a man of beautiful. Three types of alloys were studied, according to law norms of the Republic of Serbia, and needs of the market. Alloy of ,,yellow“ color is Au585Ag90Cu264Zn61, alloy of ,,white“ color is Au585Ag65Cu277Zn16Pd57, and silver alloy is Ag925Cu75. An additional alloying of basic ternary system was performed in order to improve physical – mechanical properties, such as strength of alloy, workability, ability of alloy to different kinds of plastic deformation, ability to soldering and welding, etc. As in different stages of jewelry production, especially during thermal and/or mechanic processing significant and multiple structural changes occur, changes that inflect on color of the material, and are not investigated enough; a part of this research was dedicated to coordination of investigated processing parameters with expected color of investigated alloys. Special attention, during the experimental part of the paper, was directed on investigation of regime thermal treatment in process of ageing, on temperatures below the temperature of recristallization, in order to establish the inflection of temperature and time, i chosen investigation interval, on microstructure and phase changes, that are directly connected to age-hardening of investidated alloy`s systems. Occurrence of structural changes in crystal lattice of alloys, on borders of phase changes in solid state (α(Au,Ag,Cu) ↔ α`(Ag,Au) + α”(Cu,Au)), phenomena of ,,ordered – disordered“ (forming of ordered lattices: AuCu I, AuCu II, Au3Cu and AuCu3), occurence of twining of annealing as well as other micro structural changes, bring to significant increasement in strength of this alloys. Beside these changes, there is also increasement in hardness by annealing on temperature of ageing, due to phenomena of precipitation both on borders of grains, and inside the grains, and also due to inhibition of dislocations, that now tend to release by bringing in the external energy. Hardening of investigated alloys during the process of ageing was followed by systematic examination of change of hardness value, related to initial state, and also to the state after the recristallization...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Технички факултет, Борsr
dc.rightsopenAccessen
dc.sourceУниверзитет у Београдуsr
dc.subjectlegure zlata 585sr
dc.subject585 gold alloysen
dc.subjectlegure srebra 925sr
dc.subjectzlatosr
dc.subjectsrebrosr
dc.subjectstarenjesr
dc.subjectojačavanjesr
dc.subjectmikrostrukturasr
dc.subjectkristalno sređivanjesr
dc.subjectotvrdnajvanje precipitacijomsr
dc.subjectuređenoneuređenosr
dc.subjectoptička mikroskopijasr
dc.subjectSEMsr
dc.subjectEDSsr
dc.subjecttvrdoćasr
dc.subjectelektrična provodljivostsr
dc.subjectlasersr
dc.subject925 silver alloysen
dc.subjectgolden
dc.subjectsilveren
dc.subjectageingen
dc.subjectstrengtheningen
dc.subjectmicrostructureen
dc.subjectcrystal orderingen
dc.subjecthardening by precipitationen
dc.subjectordered-diserdereden
dc.subjectoptical microscopyen
dc.subjectSEMen
dc.subjectEDSen
dc.subjecthardnessen
dc.subjectelectrical conductivityen
dc.subjectlaseren
dc.titleIspitivanje ojačavanja starenjem legura sistema Au-Ag-Cu za proizvodnju nakitesr
dc.titleInvestigation of age-hardening of alloy systems Au-Ag-Cu for jewelry productionen
dc.typedoctoralThesis
dc.rights.licenseARR
dcterms.abstractГусковић, Драгослав; Јованчићевић, Бранимир; Стојадиновић, Слободан; Иванов, Светлана; Марковић, Десимир; Перић, Радиша С.; Испитивање ојачавања старењем легура система Aу-Aг-Цу за производњу наките; Испитивање ојачавања старењем легура система Aу-Aг-Цу за производњу наките;
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/16797/Disertacija3933.pdf
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/16798/Peric_Radisa_referat_TFB.pdf


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