Browsing by Author "Forsen, Olof"
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- 10M MSM-kiteen elektrolyyttinen kiillotus
Kemian ja materiaalitieteiden tiedekunta | Bachelor's thesis(2008) Huvinen, Anne - Alumiinin käyttö nykyajan autoteollisuudessa
Kemiantekniikan korkeakoulu | Bachelor's thesis(2015-12-07) Zhang, Charlie - Amorfinen metalli - metallilasi
Kemiantekniikan korkeakoulu | Bachelor's thesis(2013-04-30) Lehtimäki, Eero - Arseenin käyttäytyminen hapettavassa pasutuksessa
Kemiantekniikan korkeakoulu | Bachelor's thesis(2014-01-16) Piskunen, Petteri - Bainiittiset teräkset
Kemian tekniikan korkeakoulu | Bachelor's thesis(2012) Lipiäinen, Harri - C/SiC-komposiitit: valmistus, ominaisuudet ja käyttökohteet
Kemiantekniikan korkeakoulu | Bachelor's thesis(2014-11-28) Mannermaa, Karri - Carbon Nanotube Fiber Pretreatments for Electrodeposition of Copper
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2018-02-11) Hannula, Pyry-Mikko; Junnila, Minttu; Janas, Dawid; Aromaa, Jari; Forsen, Olof; Lundström, MariThere is increasing interest towards developing carbon nanotube-copper (CNT-Cu) composites due to potentially improved properties. Carbon nanotube macroscopic materials typically exhibit high resistivity, low electrochemical reactivity, and the presence of impurities, which impede its use as a substrate for electrochemical deposition of metals. In this research, different CNT fiber pretreatment methods, such as heat treatment, immersion in Watts bath, anodization, and exposure to boric acid (H3BO3), were investigated to improve the electrochemical response for copper deposition. It was shown that these treatments affect the surface activity of CNTs, including electrical resistivity, polarization resistance, and active surface area, which influence the electrodeposition process of copper. Properties of CNT structures and CNT-Cu composites were researched by electrochemical impedance spectroscopy (EIS), galvanostatic copper deposition, scanning electron microscope (SEM), and four-point electrical resistance measurements. Heat treatment, Watts bath, anodization, and boric acid treatments were shown to be effective for modifying the CNT surface reactivity for subsequent electrochemical deposition of copper. - Kuparin hapettumakerrosten sähkökemiallinen karakterisointi
Helsinki University of Technology | Master's thesis(1994) Pesonen, Petteri - Eräiden kupariseosten korroosionkesto muurahaishappoliuoksissa
Helsinki University of Technology | Master's thesis(2005) Leppänen, HannaThe purpose of this thesis was to find the best corrosion resistant copper alloy for copper tubes, which are used in heat-exchanging, refrigerating and air-.conditioning units. In theoretical section of the thesis corrosion mechanism, in-Influencing factors, history and cases of formicary corrosion were studied. In same context also widely used method in reproduction test and different preventive measures based on literature survey were presented. In addition of this, I corrosion of aluminium and zinc in formic acid solution were also studied. In experimental part of the thesis the corrosion behaviour of pure copper, aluminium, tin, zinc and some copper alloys were studied in formic acid solutions. The behaviour of pure copper was also studied in sulphuric acid solutions. Linear polarization resistance, anodic and cathodic polarization and impedance measurements were used as research methods. Several electrolytic solutions were used in the investigation. In preliminary study the effect of three different formic acid solutions on pure copper was investigated. Based on this preliminary study aqueous solution containing 5 vol % formic acid was chosen and in that solution all the other materials were studied. Due to comparison the effect of pure copper was studied in two sulphuric acid solutions, which had the same pH-values as equivalent formic acid solutions. Different materials were also studied in formic acid solution whose pH-value was raised and in a solution where copper ions had added to that. In addition test similar to the reproduction test, was carried out on the copper tubes. The purpose of that test was to repeat the test and compare the results with results of other researchers. Based on tests it was concluded that pure aluminium was the least corroding metal in test conditions. However, no big differences were found in the behaviour of the different copper alloys. Copper alloy no. 12 and Nordic gold were least corroding metals in the group of copper alloys. Formicary corrosion was not noticed in reproduction test. If there were formicary corrosion on copper tubes it was very difficult to find. Based on test formicary corrosion does not seem to be an own corrosion. - Corrosion phenomena of stainless steels and brass in stagnant water environment
Kemian tekniikan korkeakoulu | Master's thesis(2016-02-02) Pylväläinen, Heini - Corson-pronssin käyttö ja lämpökäsittely
Kemian tekniikan korkeakoulu | Bachelor's thesis(2011) Kiesi, Harri - Pourbaix-diagrammien laskenta- ja piirtorutiinien kehitys
Helsinki University of Technology | Master's thesis(1997) Anttila, Kai Juhani - DEVELOPMENT OF CHARACTERIZATION METHODS FOR ADHERENT ANODE SLIMES IN COPPER ELECTROREFINING
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2016) Kiviluoma, Mikko; Aaltonen, Miamari; Aromaa, Jari; Lundström, Mari; Forsen, OlofAdherent anode slimes can cause anode passivation in copper electrorefining and lower the efficiency of copper electrorefining. Declining concentrate grades cause larger impurity levels in anodes, thus creating larger quantities of slimes in the refining process. In order to investigate the characterization methods for adherent anode slimes in copper electrorefining, experiments were conducted for the Boliden Harjavalta Pori refinery material. Methods such as particle size determination, chemical (ICP) analysis, settling rate determination, XRD, SEM-SE, SEM-BSE and SEM-EDS were applied. In addition, adherent anode slime samples were compared to optical micrograph and SEM-BSE images of respective anode copper samples. It was shown that SEM-EDS and SEM-BSE provided precise information about phases formed during electrorefining. The settling rate and particle size had a correlation only with a copper content of anode slime. The main phases in the anode slime were copper and lead sulphates as well as copper-silver selenides. NiO was shown to be the major Ni-bearing phase in the adherent slime. Nickel, tellurium and lead had the strongest, whereas arsenic, selenium and antimony had the weakest tendency to report to the anode slime. - Katodisen suojauksen ulottuminen jäänmurtajan rungolla Itämeren eri osissa
Helsinki University of Technology | Master's thesis(1999) Koivuniemi, SakuTyössä tutkittiin katodisen suojauksen leviämistä anodien ympäristössä ja suojauksen ulottuvuutta jäänmurtajan rungolla murtovedessä sekä näihin vaikuttavia tekijöitä. Lisäksi selvitettiin miten katodisen suojauksen toimivuutta Itämeren eri osissa voitaisiin parantaa. Työn kirjallisuusosassa käsiteltiin katodisen suojauksen perusteiden lisäksi suojauksen mitoitusperusteita, potentiaali- ja virranjakaumia sekä suojauksen seurantaa. Tämän lisäksi esiteltiin jäänmurtajien katodisen suojauksen toteutusta ja seurantaa. Kokeellisessa osassa käsiteltiin Teknillisen korkeakoulun korroosion ja materiaalikemian laboratoriossa suoritettujen sähkökemiallisten kokeiden perusteella suolapitoisuuden ja meriveden virtauksen vaikutusta korroosionopeuteen ja katodisen suojauksen suojavirran tarpeeseen. Suojavirran tarve murtovedessä on noin kaksi kertaa suurempi kuin valtameressä. Suojauksen alkuvaiheen virta voi kuitenkin murtovedessä paljaalle teräkselle olla 20-kertainen verrattuna valtameren veteen. Virtausnopeuden kasvu lisää suojavirran tarpeen valtameren vedessä noin 10-kertaiseksi ja murtovedessä jopa 20-kertaiseksi. Laboratoriossa suoritettiin myös kokeellista mallinnusta, jolla selvitettiin anodikilven, ylisuojauksen ja kalkkikerrostumien vaikutusta suojauksen ulottumiseen sekä suojavirran tarpeeseen. Jään- ja monitoimimurtajilla tehtyjen mittausten perusteella selvitettiin suojauksen leviämistä anodin ympäristössä sekä suojauksen ulottumista koko aluksen rungolla Itämeren eri osissa todellisissa liikennöintiolosuhteissa Potentiaalijakauma ei murtovedessä ole paljaalle teräkselle ideaalinen ja anodin lähialueet ovat selvästi ylisuojattuja. Jäänmurtajien katodinen suojaus Itämeressä on pääasiassa keskitettävä laiturissaoloaikaan, jossa suojausta voidaan parantaa riippuvilla anodeilla. Jos katodista suojausta halutaan jäänmurtajissa käyttää Perämerellä, on mekaanista rasitusta ja huomattavaa ylisuojausta kestävien anodikilpien käyttö anodien ympärillä ehdoton vaatimus suojauksen toimivuudelle. Anodikilven vaikutus on merkittävämpi murtovedessä, jossa se vähentää suojavirran tarvetta noin 70-80 %. - Effect of process variables on oxidative pressurized acid leaching of copper electrorefining anode slimes
A4 Artikkeli konferenssijulkaisussa(2016-09-16) Seisko, Sipi; Aromaa, Jari; Latostenmaa, Petri; Forsen, Olof; Lundstrom, MariExtraction of Cu, Ni, As and Te from copper electrorefining anode slimes was studied. Such parameters as sulfuric acid concentration, temperature and oxygen partial pressure had a positive effect on the oxidative pressurized acid leaching in the decreasing order in contrast to the solids concentration. For nickel extraction, temperature, sulfuric acid concentration, combined effect of temperature and sulfuric acid concentration as well as solids concentration and sulfuric acid concentration had a positive effect, in a decreasing order. In the case of arsenic extraction, combined effect of temperature and sulfuric acid concentration, temperature as well as sulfuric acid concentration had positive in the decreasing order. During tellurium extraction, none of the parameters investigated gave the statistically valid response. Basing on the regression analysis, appropriate models for the dissolution of copper and arsenic could be build. - Elektrolyysikennojen diafragmamateriaalit
Kemian ja materiaalitieteiden tiedekunta | Bachelor's thesis(2009) Pietilä, Kalle Gleb - Energiatehokkuus ja sen on-line seuranta valokaariuuniin perustuvassa terästeollisuudessa
Kemian ja materiaalitieteiden tiedekunta | Bachelor's thesis(2010) Karlsson, Mikael Isak - Epäpuhtauksien vaikutus kuparin ilmastolliseen korroosioon
Kemiantekniikan korkeakoulu | Bachelor's thesis(2015-04-20) Al-Terke, Hedar H - Factors Affecting Corrosion in Gulf of Finland Brackish Water
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2016) Aromaa, Jari; Forsen, Olof - Ferromagneettisten muistimetallien valmistustekniikat
Kemiantekniikan korkeakoulu | Bachelor's thesis(2015-04-29) Klemettinen, Lassi