TY  - JOUR
AU  - Mitrašinović, Aleksandar
AU  - Nešković, Jasmina
AU  - Polavder, Svetlana
AU  - Petković, Sandra
AU  - Praštalo, Željko
AU  - Labus, Nebojša
AU  - Radosavljević, Milinko
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16380
AB  - Advancements in computer capabilities enable predicting process outcomes that earlier could only be assessed after post-process analyses. In aerospace and automotive industries it is important to predict parts properties before their formation from liquid alloys. In this work, the logistic function was used to predict the evaporation rates of the most detrimental impurities, if the temperature of the liquid aluminum alloy was known. Then, parameters of the logistic function were used to determine the transition points where the reaction order was changing. Samples were heated to 610 °C, 660 °C, 710 °C, and 760 °C for one hour, after which the chemical analyses were performed and evaporation rates were calculated for Cd, Hg, Pb and Zn elements. The pressure inside the encapsulated area was maintained at 0.97 kPa. Whereas parameters that define the evaporation rate increase with the temperature increase, the maximum evaporation rates were deduced from the experimental data and fitted into the logistic function. The elemental evaporation in liquid-aluminum alloys is the best defined by the logistic function, since transitions from the first to zero-order-governed evaporation reactions have nonsymmetrical evaporation rate slopes between the lowest and the highest evaporation rate point.
PB  - Basel : MDPI AG
T2  - Materials
T1  - Modeling of Impurities Evaporation Reaction Order in Aluminum Alloys by the Parametric Fitting of the Logistic Function
SP  - 728
VL  - 17
IS  - 3
DO  - 10.3390/ma17030728
UR  - https://hdl.handle.net/21.15107/rcub_dais_16380
ER  - 

@article{
author = "Mitrašinović, Aleksandar and Nešković, Jasmina and Polavder, Svetlana and Petković, Sandra and Praštalo, Željko and Labus, Nebojša and Radosavljević, Milinko",
year = "2024",
abstract = "Advancements in computer capabilities enable predicting process outcomes that earlier could only be assessed after post-process analyses. In aerospace and automotive industries it is important to predict parts properties before their formation from liquid alloys. In this work, the logistic function was used to predict the evaporation rates of the most detrimental impurities, if the temperature of the liquid aluminum alloy was known. Then, parameters of the logistic function were used to determine the transition points where the reaction order was changing. Samples were heated to 610 °C, 660 °C, 710 °C, and 760 °C for one hour, after which the chemical analyses were performed and evaporation rates were calculated for Cd, Hg, Pb and Zn elements. The pressure inside the encapsulated area was maintained at 0.97 kPa. Whereas parameters that define the evaporation rate increase with the temperature increase, the maximum evaporation rates were deduced from the experimental data and fitted into the logistic function. The elemental evaporation in liquid-aluminum alloys is the best defined by the logistic function, since transitions from the first to zero-order-governed evaporation reactions have nonsymmetrical evaporation rate slopes between the lowest and the highest evaporation rate point.",
publisher = "Basel : MDPI AG",
journal = "Materials",
title = "Modeling of Impurities Evaporation Reaction Order in Aluminum Alloys by the Parametric Fitting of the Logistic Function",
pages = "728",
volume = "17",
number = "3",
doi = "10.3390/ma17030728",
url = "https://hdl.handle.net/21.15107/rcub_dais_16380"
}

Mitrašinović, A., Nešković, J., Polavder, S., Petković, S., Praštalo, Ž., Labus, N.,& Radosavljević, M.. (2024). Modeling of Impurities Evaporation Reaction Order in Aluminum Alloys by the Parametric Fitting of the Logistic Function. in Materials
Basel : MDPI AG., 17(3), 728.
https://doi.org/10.3390/ma17030728
https://hdl.handle.net/21.15107/rcub_dais_16380

Mitrašinović A, Nešković J, Polavder S, Petković S, Praštalo Ž, Labus N, Radosavljević M. Modeling of Impurities Evaporation Reaction Order in Aluminum Alloys by the Parametric Fitting of the Logistic Function. in Materials. 2024;17(3):728.
doi:10.3390/ma17030728
https://hdl.handle.net/21.15107/rcub_dais_16380 .

Mitrašinović, Aleksandar, Nešković, Jasmina, Polavder, Svetlana, Petković, Sandra, Praštalo, Željko, Labus, Nebojša, Radosavljević, Milinko, "Modeling of Impurities Evaporation Reaction Order in Aluminum Alloys by the Parametric Fitting of the Logistic Function" in Materials, 17, no. 3 (2024):728,
https://doi.org/10.3390/ma17030728 .,
https://hdl.handle.net/21.15107/rcub_dais_16380 .

TY  - JOUR
AU  - Mitrašinović, Aleksandar
AU  - Nešković, Jasmina
AU  - Ristić, Ognjen
AU  - Labus, Nebojša
AU  - Radosavljević, Milinko
AU  - Odanović, Zoran
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16170
AB  - Jedan od najefikasnijih načina za buduće projektovanje, proizvodnju, analizu i optimizaciju novih procesa koji uključuju faznu promenu materijala je razvoj visokoosetljivih kvantitativnih metoda zasnovanih na detekciji temperaturnih promena tokom trajanja procesa i korelaciji tih promena sa promenama u tretiranom materijalu. U ovom radu, sekundarna legura Al-8wt%Si-3wt%Cu je formirana iz tečnog stanja u uslovima slobodnog hlađenja. Identifikovane su karakteristične temperature transformacija i formalizovan je metod za praćenje količine čvrste faze tokom procesa očvršćavanja. Iz snimljene krive hlađenja određene su vrednosti prvog izvoda i formirana je odgovarajuća referentna kriva. Površina između prvog izvoda krive hlađenja i referentne krive je korišćena za praćenje količine očvrslog dela materijala tokom procesa očvršćavanja. Dobijeni rezultati su pokazali da je predložena metoda efikasna u dobijanju podataka o količini očvrslog dela materijala u svakom trenutku procesa očvršćavanja, kao i da se mogu dalje koristiti za detekciju broja faza i mikrokonstituenata u formiranoj strukturi i eksperimentalnu potvrdu latentne toplote očvršćavanja novih materijala. Metoda praćenja količine formirane čvrste faze u uslovima slobodnog hlađenja ne zahteva posebnu pripremu uzoraka niti kompleksnu laboratorijsku opremu, pa shodno tome, u praktičnoj primeni efikasno zamenjuje standardne metode za detekciju termofizičkih osobina materijala, kao što su diferencijalna termijska analiza ili diferencijalna skenirajuća kalorimetrija.
AB  - One of the most effective ways for the future design, production, analysis and optimization of new processes, involving phase change of materials, is the development of highly sensitive quantitative methods based on the detection of temperature changes during the solidification process and the correlation of these changes with changes in the treated material. In this work, the secondary Al-8wt%Si3wt%Cu alloy was formed from the liquid state under free cooling conditions. Characteristic transformation temperatures were identified and a method for monitoring the amount of solid phase during the solidification process was formalized. From the recorded cooling curve, the values of the first derivative were determined and the corresponding reference curve was formed. The area between the first derivative of the cooling curve and the reference curve was used to assess the amount of solidified part of the material during the solidification process. The obtained results showed that the proposed method is effective in obtaining data of the fraction solid at every moment of the solidifcation process, as well as that it can be further used to detect the number of phases and microconstituents in the formed structure, as well as an experimental examination of the latent heat of solidification of new materials. The method of monitoring the amount of solid phase, formed under free cooling conditions, does not require specific preparation of samples or complex laboratory equipment, and accordingly, in practical application it effectively replaces standard methods for detecting thermophysical properties of materials, such as differential thermal analysis or differential scanning calorimetry.
PB  - Beograd : Savez inženjera i tehničara Srbije
T2  - Tehnika
T1  - Praćenje količine formirane čvrste faze u leguri aluminijuma u uslovima slobodnog hlađenja
SP  - 138
EP  - 144
VL  - 78
IS  - 2
DO  - 10.5937/tehnika2302138M
UR  - https://hdl.handle.net/21.15107/rcub_dais_16170
ER  - 

@article{
author = "Mitrašinović, Aleksandar and Nešković, Jasmina and Ristić, Ognjen and Labus, Nebojša and Radosavljević, Milinko and Odanović, Zoran",
year = "2023",
abstract = "Jedan od najefikasnijih načina za buduće projektovanje, proizvodnju, analizu i optimizaciju novih procesa koji uključuju faznu promenu materijala je razvoj visokoosetljivih kvantitativnih metoda zasnovanih na detekciji temperaturnih promena tokom trajanja procesa i korelaciji tih promena sa promenama u tretiranom materijalu. U ovom radu, sekundarna legura Al-8wt%Si-3wt%Cu je formirana iz tečnog stanja u uslovima slobodnog hlađenja. Identifikovane su karakteristične temperature transformacija i formalizovan je metod za praćenje količine čvrste faze tokom procesa očvršćavanja. Iz snimljene krive hlađenja određene su vrednosti prvog izvoda i formirana je odgovarajuća referentna kriva. Površina između prvog izvoda krive hlađenja i referentne krive je korišćena za praćenje količine očvrslog dela materijala tokom procesa očvršćavanja. Dobijeni rezultati su pokazali da je predložena metoda efikasna u dobijanju podataka o količini očvrslog dela materijala u svakom trenutku procesa očvršćavanja, kao i da se mogu dalje koristiti za detekciju broja faza i mikrokonstituenata u formiranoj strukturi i eksperimentalnu potvrdu latentne toplote očvršćavanja novih materijala. Metoda praćenja količine formirane čvrste faze u uslovima slobodnog hlađenja ne zahteva posebnu pripremu uzoraka niti kompleksnu laboratorijsku opremu, pa shodno tome, u praktičnoj primeni efikasno zamenjuje standardne metode za detekciju termofizičkih osobina materijala, kao što su diferencijalna termijska analiza ili diferencijalna skenirajuća kalorimetrija., One of the most effective ways for the future design, production, analysis and optimization of new processes, involving phase change of materials, is the development of highly sensitive quantitative methods based on the detection of temperature changes during the solidification process and the correlation of these changes with changes in the treated material. In this work, the secondary Al-8wt%Si3wt%Cu alloy was formed from the liquid state under free cooling conditions. Characteristic transformation temperatures were identified and a method for monitoring the amount of solid phase during the solidification process was formalized. From the recorded cooling curve, the values of the first derivative were determined and the corresponding reference curve was formed. The area between the first derivative of the cooling curve and the reference curve was used to assess the amount of solidified part of the material during the solidification process. The obtained results showed that the proposed method is effective in obtaining data of the fraction solid at every moment of the solidifcation process, as well as that it can be further used to detect the number of phases and microconstituents in the formed structure, as well as an experimental examination of the latent heat of solidification of new materials. The method of monitoring the amount of solid phase, formed under free cooling conditions, does not require specific preparation of samples or complex laboratory equipment, and accordingly, in practical application it effectively replaces standard methods for detecting thermophysical properties of materials, such as differential thermal analysis or differential scanning calorimetry.",
publisher = "Beograd : Savez inženjera i tehničara Srbije",
journal = "Tehnika",
title = "Praćenje količine formirane čvrste faze u leguri aluminijuma u uslovima slobodnog hlađenja",
pages = "138-144",
volume = "78",
number = "2",
doi = "10.5937/tehnika2302138M",
url = "https://hdl.handle.net/21.15107/rcub_dais_16170"
}

Mitrašinović, A., Nešković, J., Ristić, O., Labus, N., Radosavljević, M.,& Odanović, Z.. (2023). Praćenje količine formirane čvrste faze u leguri aluminijuma u uslovima slobodnog hlađenja. in Tehnika
Beograd : Savez inženjera i tehničara Srbije., 78(2), 138-144.
https://doi.org/10.5937/tehnika2302138M
https://hdl.handle.net/21.15107/rcub_dais_16170

Mitrašinović A, Nešković J, Ristić O, Labus N, Radosavljević M, Odanović Z. Praćenje količine formirane čvrste faze u leguri aluminijuma u uslovima slobodnog hlađenja. in Tehnika. 2023;78(2):138-144.
doi:10.5937/tehnika2302138M
https://hdl.handle.net/21.15107/rcub_dais_16170 .

Mitrašinović, Aleksandar, Nešković, Jasmina, Ristić, Ognjen, Labus, Nebojša, Radosavljević, Milinko, Odanović, Zoran, "Praćenje količine formirane čvrste faze u leguri aluminijuma u uslovima slobodnog hlađenja" in Tehnika, 78, no. 2 (2023):138-144,
https://doi.org/10.5937/tehnika2302138M .,
https://hdl.handle.net/21.15107/rcub_dais_16170 .

TY  - JOUR
AU  - Mitrašinović, Aleksandar
AU  - Nešković, Jasmina
AU  - Labus, Nebojša
AU  - Radosavljević, Milinko
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14224
AB  - Očvršćavanje legura aluminijuma se najčešće odvija u termootpornim oblogama sačinjenim ili od metala ili od oksida koji su stabilni na visokim temperaturama. Značajno različita toplotna provodljivost između metala i termootpornih oksida prouzrokuje očvršćavanje sa različitim brzinama hlađenja. U ovom radu smo formirali sekundarnu leguru Al-8wt%Si-3wt%Cu u kalupu od nerđajućeg čelika, tankozidnoj čaši od nerđajućeg čelika i debelozidnoj čaši od cirkonijum oksida. Tok formiranja očvrsle strukture je praćen zaronjenim termoparovima koji su omogućili kompjutersku analizu krive hlađenja. Parametri na koje je brzina hlađenja imala najznačajniji uticaj su vrednosti pothlađenja formiranja primarnih kristala aluminijuma, vreme rasta primarnih kristala aluminijuma i ukupno vreme očvršćavanja od pojave prvih čvrstih kristala do formiranja potpuno očvrsle strukture. Al-8wt%Si-3wt%Cu legura aluminijuma formirana u metalnim kalupima ima manju veličinu zrna i posledočno veću zateznu čvrstoću, manju makroporoznost i manje hrapavu površinu od legure formirane u oblogama od termootpornih oksida. Ispitivane termootporne obloge su uticale na formiranje tri osnovna mikrokonstituenta u Al-8wt%Si-3wt%Cu leguri u različitim vremenskim intervalima, što je dovelo do formiranja različite mikrostrukture, gde odluka o izboru materijala termootporne obloge zavisi od isplativosti celokupnog procesa, zahtevanog kvaliteta spoljnih površina i zahtevane minimalne čvrstoće konačnog proizvoda.
AB  - Solidification of the aluminum alloys takes place in heat-resistant refractory materials made of either metal or oxides that are stable at high temperatures. The significantly different thermal conductivities between metals and heat-resistant oxides cause solidification with significantly different cooling rates. In this work, we formed a secondary Al-8wt%Si-3wt%Cu alloy in a stainless steel mould, a thin-walled stainless steel cup, and a thick-walled zirconium oxide cup. The course of the formation of the solidified structure was monitored by immersed thermocouples, which enabled the computer analysis of the cooling curves. The parameters on which the cooling rate had the most significant influence are the undercooling values of the formation of primary aluminum crystals, the time of the growth of primary aluminum crystals and the total solidification time from the formation of the first solid crystals to the formation of a fully solidified structure. The Al-8wt%Si-3wt%Cu aluminum alloy formed in metal mould has a smaller grain size and consequently higher tensile strength, lower macro-porosity and less rough surface than the alloy formed in refractory oxide coatings. The examined heat-resistant refractory material influenced the formation of three basic micro-constituents in the Al-8wt%Si-3wt%Cu alloy in different time intervals, which led to the formation of a different microstructure, where the decision on the choice of material for the heat-resistant refractory material depends on the profitability of the entire process, the required quality of the external surfaces and required minimum strength of the final product.
PB  - Beograd : Savez inženjera i tehničara Srbije
T2  - Tehnika
T1  - The effect of the refractory material on the phase transformation parameteres during forming of the Al-8wt%Si-3wt%Cu structure
T1  - Uticaj termootporne obloge na parametre fazne transformacije tokom formiranja Al-8wt%Si-3wt%Cu strukture
SP  - 9
EP  - 14
VL  - 78
IS  - 1
DO  - 10.5937/tehnika2301009M
UR  - https://hdl.handle.net/21.15107/rcub_dais_14224
ER  - 

@article{
author = "Mitrašinović, Aleksandar and Nešković, Jasmina and Labus, Nebojša and Radosavljević, Milinko",
year = "2023",
abstract = "Očvršćavanje legura aluminijuma se najčešće odvija u termootpornim oblogama sačinjenim ili od metala ili od oksida koji su stabilni na visokim temperaturama. Značajno različita toplotna provodljivost između metala i termootpornih oksida prouzrokuje očvršćavanje sa različitim brzinama hlađenja. U ovom radu smo formirali sekundarnu leguru Al-8wt%Si-3wt%Cu u kalupu od nerđajućeg čelika, tankozidnoj čaši od nerđajućeg čelika i debelozidnoj čaši od cirkonijum oksida. Tok formiranja očvrsle strukture je praćen zaronjenim termoparovima koji su omogućili kompjutersku analizu krive hlađenja. Parametri na koje je brzina hlađenja imala najznačajniji uticaj su vrednosti pothlađenja formiranja primarnih kristala aluminijuma, vreme rasta primarnih kristala aluminijuma i ukupno vreme očvršćavanja od pojave prvih čvrstih kristala do formiranja potpuno očvrsle strukture. Al-8wt%Si-3wt%Cu legura aluminijuma formirana u metalnim kalupima ima manju veličinu zrna i posledočno veću zateznu čvrstoću, manju makroporoznost i manje hrapavu površinu od legure formirane u oblogama od termootpornih oksida. Ispitivane termootporne obloge su uticale na formiranje tri osnovna mikrokonstituenta u Al-8wt%Si-3wt%Cu leguri u različitim vremenskim intervalima, što je dovelo do formiranja različite mikrostrukture, gde odluka o izboru materijala termootporne obloge zavisi od isplativosti celokupnog procesa, zahtevanog kvaliteta spoljnih površina i zahtevane minimalne čvrstoće konačnog proizvoda., Solidification of the aluminum alloys takes place in heat-resistant refractory materials made of either metal or oxides that are stable at high temperatures. The significantly different thermal conductivities between metals and heat-resistant oxides cause solidification with significantly different cooling rates. In this work, we formed a secondary Al-8wt%Si-3wt%Cu alloy in a stainless steel mould, a thin-walled stainless steel cup, and a thick-walled zirconium oxide cup. The course of the formation of the solidified structure was monitored by immersed thermocouples, which enabled the computer analysis of the cooling curves. The parameters on which the cooling rate had the most significant influence are the undercooling values of the formation of primary aluminum crystals, the time of the growth of primary aluminum crystals and the total solidification time from the formation of the first solid crystals to the formation of a fully solidified structure. The Al-8wt%Si-3wt%Cu aluminum alloy formed in metal mould has a smaller grain size and consequently higher tensile strength, lower macro-porosity and less rough surface than the alloy formed in refractory oxide coatings. The examined heat-resistant refractory material influenced the formation of three basic micro-constituents in the Al-8wt%Si-3wt%Cu alloy in different time intervals, which led to the formation of a different microstructure, where the decision on the choice of material for the heat-resistant refractory material depends on the profitability of the entire process, the required quality of the external surfaces and required minimum strength of the final product.",
publisher = "Beograd : Savez inženjera i tehničara Srbije",
journal = "Tehnika",
title = "The effect of the refractory material on the phase transformation parameteres during forming of the Al-8wt%Si-3wt%Cu structure, Uticaj termootporne obloge na parametre fazne transformacije tokom formiranja Al-8wt%Si-3wt%Cu strukture",
pages = "9-14",
volume = "78",
number = "1",
doi = "10.5937/tehnika2301009M",
url = "https://hdl.handle.net/21.15107/rcub_dais_14224"
}

Mitrašinović, A., Nešković, J., Labus, N.,& Radosavljević, M.. (2023). The effect of the refractory material on the phase transformation parameteres during forming of the Al-8wt%Si-3wt%Cu structure. in Tehnika
Beograd : Savez inženjera i tehničara Srbije., 78(1), 9-14.
https://doi.org/10.5937/tehnika2301009M
https://hdl.handle.net/21.15107/rcub_dais_14224

Mitrašinović A, Nešković J, Labus N, Radosavljević M. The effect of the refractory material on the phase transformation parameteres during forming of the Al-8wt%Si-3wt%Cu structure. in Tehnika. 2023;78(1):9-14.
doi:10.5937/tehnika2301009M
https://hdl.handle.net/21.15107/rcub_dais_14224 .

Mitrašinović, Aleksandar, Nešković, Jasmina, Labus, Nebojša, Radosavljević, Milinko, "The effect of the refractory material on the phase transformation parameteres during forming of the Al-8wt%Si-3wt%Cu structure" in Tehnika, 78, no. 1 (2023):9-14,
https://doi.org/10.5937/tehnika2301009M .,
https://hdl.handle.net/21.15107/rcub_dais_14224 .