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Optimization of the production process of battery packs for electric vehicles
No full textTema ovog rada je optimizacija proizvodnih procesa primjenom Lean Six Sigma metodologije. Kroz prvi dio rada daje se teorijska podloga o samoj metodologiji koja se nametnula kao odličan pristup za postizanje operativne izvrsnosti i optimizaciju proizvodnih procesa. U nastavku se detaljno obrađuju alati Lean Six Sigma metodologije koji će se primijeniti u praktičnom dijelu rada i koji su odličan korak prema optimizaciji procesa u proizvodnji. Nakon temeljitog proučavanja relevantne literature u prvom dijelu rada, drugi dio fokusira se na praktičnu primjenu stečenog znanja s ciljem poboljšanja proizvodnih procesa. U praktičnom dijelu mapirani su procesi proizvodnje baterijskih paketa električnih vozila i detektirane nesukladnosti koje se događaju unutar procesa. Nakon identificiranja nesukladnosti napravljena je analiza potencijalnih uzroka, prikaz rješenja tih nesukladnosti i pristup prema njihovoj prevenciji u budućnosti. U drugom dijelu napravljen je Ishikawa dijagram s ciljem rješavanja aktualnih uzroka problema kako bi se zadovoljili dogovoreni rokovi projekta te su za svaki od glavnih uzroka problema dani prijedlozi rješenja.The topic of this paper is the optimization of production processes using the Lean Six Sigma methodology. Through the first part of the paper, the theoretical background is given on the methodology itself, which has been imposed as an excellent approach for achieving operational excellence and production processes optimization. In the continuation of the paper, the tools of the Lean Six Sigma methodology that will be applied in the practical part of the work and which are an excellent step towards optimizing the production process are discussed in detail. After a thorough study of the relevant literature in the first part of the paper, the second part focuses on the practical application of the acquired knowledge with the aim of improving production processes. In the practical part, the production processes of electric vehicle battery packs are mapped and non-conformities that occur within the process are detected. After identifying the non-conformities, an analysis of potential causes was made, a presentation of solutions to these non-conformities and an approach to their prevention in the future. In the second part, an Ishikawa diagram was created with the aim of solving the current causes of the problem in order to meet the agreed project deadlines, also suggestions for solutions were provided for each of the main causes of the problems
Comparison of numerical and experimental values of impact damage at aircraft horizontal stabilizer structure
No full textProučavanje udarnih opterećenja i oštećenja na kompozitne konstrukcije eksperimentalnim ispitivanjem i numeričkim modeliranjem predstavlja perspektivno područje znanstvenih istraživanja, ali istovremeno donosi i brojne izazove uslijed specifičnih konstrukcija, anizotropne prirode materijala i složenih međudjelovanja kompozitnih slojeva.
U ovom se radu razmatra udar projektila u kompozitnu konstrukciju napadnog ruba horizontalnog stabilizatora pri velikim brzinama te se rezultati provedenih simulacija uspoređuju s rezultatima provedenog eksperimentalnog ispitivanja provedenog od strane partnera iz industrije. Detalji o partneru iz industrije se ne iznose zbog ugovora o tajnosti podataka.
Tijekom razvoja numeričkog modela razmatrana su tri načina opisivanja udarača. Model ptice koja udara u konstrukciju horizontalnog stabilizatora modeliran je pomoću klasičnog Lagrangeovog, SPH (eng. Smoothed Particle Hydrodynamics) i CEL (eng. Couple Eulerian-Lagrangian) pristupa. Za provođenje simulacije koristi se komercijalno dostupan programski paket za rješavanje metodom konačnih elemenata Abaqus/Explicit. Nakon usporedbe sva tri modela udarača s rezultatima ispitivanja dostupnima u literaturi definiran je numerički model koji je razvijen na temelju testnog postava korištenog za provođenje eksperimentalnog ispitivanja. Geometrija napadnog ruba opisuje se kombinacijom konvencionalnih ljuskastih elemenata i ljusaka s određenom debljinom, dok se ostatak testnog postava modelira klasičnim trodimenzionalnim elementima. U simulacijama se koristi Hashinov kriterij popuštanja kako bi se opisalo ponašanje kompozita ojačanog vlaknima.
Rezultati razmatranih simulacija uspoređeni su međusobno i s eksperimentalnih vrijednostima te se analizira poklapanje rezultata simulacija s rezultatima eksperimentalnog ispitivanja.
Na posljetku se provodi optimizacija rasporeda sojeva kompozitnog napadnog ruba te se zaključuje da postoje rasporedi slojeva koji pokazuju bolja mehanička svojstva.Exploring impact loads and damage on composite materials through experimental investigation and numerical modeling represents a promising field of scientific research, but at the same time a challenging domain due to laminated structure, anisotropic material nature, and complex layer interfaces of composites.
The subject of this thesis is modeling of a high velocity bird impact on a composite leading edge of a horizontal stabilizer and comparing the results of the simulation to the experimental dana provided by the industrial partner. Details about the industrial partner are not disclosed due to the confidentiality agreement.
In order to develop the numerical model of a high velocity impactor, three different approaches have been considered. Bird impactor model has been developed using classical Lagrangian, Smoothed Particle Hydrodynamics (SPH), and Couple Eulerian-Lagrangian (CEL) method. Commercially available software for finite element method analysis Abaqus/Explicit has been used to conduct simulations. After validating each impactor model with experimental results available in literature, a complete numerical model of the test setup has been developed to replicate the setup used in experimental testing. The geometry of leading edge is described using a combination of conventional shell and continuum shell elements, while the rest of the test setup is modeled using 3-dimensional elements. In simulations conducted, Hashin failure criteria was employed to describe the behavior of fiber-reinforced composite.
The results of all three simulation approaches have been compared with the experimental dana, and quality of results for each method has been discussed.
Optimization of the composite leading edge has been conducted and conclusions on improving the layup have been made
Characterization of biodegradable waste
No full textNepravilno gospodarenje otpadom dovodi do štetnih posljedica u okolišu uz rizik za javno zdravlje. Poznavanje svojstava otpada ključno je za iskorištavanje njegovog potencijala, čija oporaba postaje ozbiljan izazov diljem svijeta. Osim što stvara potencijalne ekološke probleme, otpad ne samo da predstavlja gubitke iz proizvodnog procesa vrijednih sirovina i energije, već zahtijeva i značajna ulaganja u kontrolu onečišćenja. U ovom radu provedena je karakterizacija organske frakcije miješanog komunalnog otpada simulacijom procjedne vode u laboratorijskim uvjetima. Rezultati pokazuju da udio biorazgradive organske frakcije u miješanom komunalnom otpadu je veći od 61,5 % uz visoku prosječnu vrijednost omjera BPK5/KPK od 0,80±0,05 što ukazuje na značajan potencijal za biološku valorizaciju ispitivanog realnog uzorka.Improper waste management leads to harmful environmental consequences and poses risks to public health. Understanding the properties of waste is crucial for harnessing its potential, and its recovery is becoming a serious challenge worldwide. Besides creating potential ecological problems, waste not only represents losses of valuable raw materials and energy from the production process, but also requires significant investments in pollution control.
In this study, the characterization of the organic fraction of mixed municipal waste was conducted by simulating leachate in laboratory conditions. The results show that the biodegradable organic fraction in mixed municipal waste is over 61.5%, with a high average BOD5/COD ratio of 0.80±0.05, indicating significant potential for biological valorization of the tested real sample
Investigation of efficiency of different cooling methods for pouch battery cells
No full textU diplomskom radu provedeno je ispitivanje hlađenja vrećastih ćelija na četiri ćelije, pri čemu
je svaka podvrgnuta različitoj vrsti hlađenja. Svaka ćelija opremljena je s 28 temperaturnih
senzora, ravnomjerno raspoređenih po površini, kako bi se osiguralo precizno praćenje
temperature tijekom ispitivanja. Ispitivanje je provedeno prema unaprijed definiranoj ispitnoj
proceduri, a svaki slučaj hlađenja obuhvaćao je nekoliko podslučajeva.
U prvom slučaju analizirano je hlađenje terminala: najprije pozitivnog, zatim negativnog, a
potom oba terminala istovremeno. Drugi slučaj uključivao je hlađenje jedne strane ćelije, a
zatim obje strane. U trećem slučaju ispitano je hlađenje jednog ruba ćelije, kao i oba ruba
istovremeno. Konačno, četvrti slučaj primijenio je kombinirano hlađenje, koje je obuhvatilo
hlađenje terminala i strana ćelije.
Rezultati pokazuju da je četvrti, kombinirani način hlađenja najučinkovitiji. Ovaj pristup
omogućio je postizanje najnižih i najravnomjernijih temperatura tijekom ispitivanja,
osiguravajući optimalne toplinske uvjete za rad ćelije. Zaključci istraživanja ističu važnost
kombiniranog pristupa hlađenju za učinkovito toplinsko upravljanje u vrećastim ćelijama.The Masters’ thesis presents the cooling examination of pouch cells, which was conducted on
four cells, each subjected to a different type of cooling. Each cell was equipped with 28
temperature sensors, evenly distributed across its surface, to ensure precise temperature
monitoring during the tests. The testing was carried out according to a predefined test
procedure, with each cooling scenario comprising several sub-cases.
In the first scenario, terminal cooling was analyzed: first the positive terminal, then the negative
terminal and finally both terminals simultaneously. The second scenario involved cooling one
side of the cell, followed by cooling both sides. In the third scenario, cooling of one edge of the
cell was tested, as well as cooling of both edges simultaneously. Finally, the fourth scenario
implemented combined cooling, which included cooling of the terminals and the sides of the
cell.
The results indicate that the fourth, combined cooling method was the most effective. This
approach achieved the lowest and most uniform temperatures during testing, ensuring optimal
thermal conditions for cell operation. The study’s conclusions highlight the importance of a
combined cooling approach for efficient thermal management in pouch cells
Device for testing the battery pack in case of self-ignition
No full textTema ovog rada je razvoj uređaja za sigurno i jednostavno testiranje baterijskih paketa u slučaju samozapaljenja jedne od ćelija unutar samog paketa. Automobilska industrija se trenutno okreće prema elektrifikaciji vozila kao odgovor na zagađenje okoliša uzrokovano ispušnim plinovima vozila s motorima na unutarnje izgaranje. Električni automobili kao izvor energije koriste električnu struju koja se pohranjuje unutar ćelija baterijskog paketa. Svaki baterijski paket pohranjuje velike količine energije koja se u slučaju oštećenja ćelija unutar paketa oslobađa u obliku naglog izgaranja ćelije što uzrokuje požar automobila. Upravo zbog toga su potrebne ovakve naprave koje će na siguran i ponovljiv način moći testirati različite dizajne baterijskih paketa kako bi elektrićni auti mogli biti sigurniji. U radu je provedena analiza tržišta i postojećih rješenja za ovakve naprave. Također su provedeni intervjui s inženjerima tvrtke Rimac technology koji su opisali svoje glavne zahtjeve za ovu napravu budući da će oni koristiti ovakvu napravu za testiranje svojih baterijskih paketa. Inženjeri su također dali neke od zahtjeva koje uređaj mora zadovoljiti te okvirne dimenzije paketa i modula koji bi se testirali u uređaju. Potom je napravljena funkcijska dekompozicija uređaja na temelju koje je napravljena morfološka tablica. Kombinacijom različitih rješenja za određene funkcije uređaja napravljeno je četiri koncepta koji su se međusobno vrednovali na temelju različitih kriterija. Najbolje ocijenjeni koncept se potom konstrukcijski razradio nakon čega je napravljen 3D model te tehnička dokumentacija naprave.The topic of this paper is the development of a device for safe and simple testing of battery packs in case of self-ignition of one of the cells inside the pack itself. The automotive industry is currently turning to the electrification of its vehicles in response to the environmental pollution caused by the exhaust gases of vehicles with internal combustion engines. Electric cars use electricity stored inside the cells of the battery pack as an energy source. Each battery pack stores large amounts of energy, which in case of damage to the cells inside the pack is released in the form of a sudden combustion of the cells, which causes a car fire. This is exactly why devices like this are needed to test different designs of battery packs in a safe and reproducible way so that the electric cars can be safer. In the paper, an analysis of the market and existing solutions for such devices was carried out. Interviews were also conducted with Rimac technology engineers who described their main requirements for this device since they will be using this device to test their battery packs. Engineers also provided some of the requirements that the device must meet for the approximate dimensions of the packages and modules that would be tested in the device. Also, a functional decomposition of the device was made, on the basis of which a morphological table was made. By combining different solutions for certain functions of the device, four concepts were created, which were evaluated against each other based on different criteria. The best-rated concept was then further developed, after which a 3D model and technical documentation of the device was created
Robotically assisted tunnel placement in ACL reconstruction of the knee
No full textU sklopu završnog rada napravljen je konceptualni prijedlog rješenja za robotski potpomognutu rekonstrukciju prednjeg križnog ligament koljena. Identificirani su ključni dijelovi operativnog zahvata te je napravljena detaljna tehnička razrada procesa bušenja tunela pomoću robota na femuru i tibiji. U uvodnom dijelu se opisuje područje medicinske robotike te provodi istraživanje trenutnih medicinskih robotskih sustava koji se koriste u ortopedskim operacijama. Uz detaljno opisivanje anatomije koljena i prednjeg križnog ligamenta (ACL) provedena je analiza trenutnog artroskopskog pristupa prilikom operacije. Opisan je tijek operativnog zahvata u svrhu njihove implementacije na robotskom rješenju. Za metodu predoperativne i intraoperativne lokalizacije korišten je NDI Polaris Spectra sustav koji je danas vodilja u svijetu operacija vođenih pomoću kamere te uz to opisan i postupak krute registracije pacijenta. Proveden je idejni plan operativnog zahvata na anonimiziranoj CT snimci stvarnog pacijenta. U sklopu simulacije cijelog operativnog zahvata ali i potrebne analize mogućih robotskih rješenja napravljena je virtualna operacijska sala unutar programa RoboDK. Provedenim simulacijama napravljena je analiza radnog područja robota s predloženim alatom te je prikazom rezultata simulacije dobivena uspješnost pojedinog robota za ostvarivanje koncipiranih kretnji. U sklopu medicinskog laboratorija u CRTA-i napravljen je fizički postav ispred robota KUKA LBR Med 7 R800 te je u stvarnosti implementiran Polaris Spectra sustav. Sve navedene metode koncipirane su u svrhu uspješnog i preciznog bušenja tunela (engl. tunnel placement) s kojim je cilj nekad u budućnosti ostvariti bolje rezultate u području rekonstrukcije ligamenata koljena.Within the scope of the bachelor thesis, a conceptual proposal for a robot-assisted reconstruction of the anterior cruciate ligament (ACL) of the knee was developed. The key parts of the surgical procedure were identified, and a detailed technical elaboration of the tunnel drilling process using robots on the femur and tibia was conducted. The introductory section describes the field of medical robotics and investigates current medical robotic systems used in orthopedic surgeries. Along with a detailed description of the anatomy of the knee and the anterior cruciate ligament (ACL), an analysis of the current arthroscopic approach during surgery was conducted. The course of the surgical procedure is described for the purpose of its implementation in the robotic solution. The NDI Polaris Spectra system, which is a leader in the world of camera-guided operations today, was used for preoperative and intraoperative localization methods, and the process of rigid patient registration is also described. The conceptual plan of the surgical procedure was carried out on an anonymized CT scan of a real patient. As part of simulating the entire surgical procedure and the necessary analysis of possible robotic solutions, a virtual operating room was created within the RoboDK program. Through the conducted simulations, an analysis of the robot's working area with the proposed tool was made, and the results of the simulation showed the effectiveness of each robot in achieving the conceived movements. Within the medical laboratory at CRTA, a physical setup in front of the KUKA LBR Med 7 R800 robot was created, and the Polaris Spectra system was implemented in reality. All the mentioned methods were conceived for the purpose of achieving successful and precise tunnel placement, with the goal of achieving better outcomes in the field of knee ligament reconstruction in the future
Utjecaj topologije i volumenskog udjela na integritet 3D tiskanih komponenti opterećenih na savijanje
No full textAn introduction to Additive Manufacturing (AM) technologies with a focus on 3D metal printing was given, and a short overview of the theory related to cellular porous structures, in particular, to Triply Periodic Minimal Surface (TPMS) structures was presented. Porous materials offer not only direct benefits such as lighter construction, material savings, and improved physical properties but also indirect advantages stemming from their widespread application in industries like aerospace and automotive, leading to fuel savings and environment protection. In this thesis the effect of specific weight and the type of cellular porous structure on the failure behaviour of a beam specimen subjected to bending was investigated. Three distinct structures (Schoen IWP, Fischer-Koch S, and Schoen F-RD), with five different specific weights, made from AlSi10Mg aluminium alloy using Direct Laser Metal Sintering (DMLS) technology were examined. A three-point bending test was conducted at room temperature using a Zwick/Roell 1456 universal testing machine to assess sample failure.
The bending forces with respect to specimens’ deflection were recorded, and energy absorption and ductility indices were computed in order to investigate the effects of the three different porous structures and their specific weight on the bending strength of the considered specimens. It was observed from the experimental results that specimens with lower specific weight can bear relatively higher load compared to specimens with higher specific weight. Furthermore, in fractured specimens crack extension was influenced by the type of structure, suggesting that future control of crack propagation could be achieved through geometrical arrangements of pores.Dan je uvod u tehnologije aditivne proizvodnje (AM) s fokusom na 3D ispis metala, te je dan kratak pregled teorije vezane uz stanične porozne strukture, posebice strukture trostruko periodične minimalne površine (TPMS). Porozni materijali nude ne samo izravne prednosti kao što su lakša konstrukcija, ušteda materijala i poboljšana fizička svojstva, već i neizravne prednosti koje proizlaze iz njihove široke primjene u industrijama poput zrakoplovne i automobilske, što dovodi do uštede goriva i zaštite okoliša. U ovom diplomskom radu istražen je utjecaj specifične težine i vrste stanične porozne strukture na ponašanje pri slomu savijanja uzorka grede. Ispitane su tri različite strukture (Schoen IWP, Fischer-Koch S i Schoen F-RD), s pet različitih specifičnih težina, izrađene od AlSi10Mg aluminijske legure korištenjem tehnologije izravnog laserskog sinteriranja metala (DMLS). Ispitivanje savijanjem u tri točke provedeno je na sobnoj temperaturi korištenjem Zwick/Roell 1456 univerzalnog ispitnog stroja za procjenu kvara uzorka.
Zabilježene su sile savijanja s obzirom na otklon uzoraka, a izračunati su indeksi apsorpcije energije i duktilnosti kako bi se istražili učinci triju različitih poroznih struktura i njihove specifične težine na čvrstoću savijanja razmatranih uzoraka. Iz rezultata pokusa uočeno je da uzorci manje specifične težine mogu podnijeti relativno veće opterećenje u odnosu na uzorke veće specifične težine. Nadalje, u slomljenim uzorcima na širenje pukotine utjecao je tip strukture, što sugerira da bi se buduća kontrola širenja pukotine mogla postići pomoću geometrijskog rasporeda pora
Structural design of composite passenger catamaran
No full textCilj ovog rada je projektiranje konstrukcije kompozitnog putničkog katamarana, na osnovu idejnog projekta izrađenog u tvrtki „iCat“.
Projektiranje je provedeno kroz dvije faze. U prvoj fazi razrađene su tri projektne varijante. Provedeno je dimenzioniranje elemenata oplate i orebrenja prema pravilima klasifikacijskog društva Hrvatskog Registra Brodova (HRB). Zatim slijedi provjera lokalne čvrstoće prema softveru ComposeIT klasifikacijskog društva Bureau Veritas (BV) te usporedba rezultata i izbor najpovoljnije projektne varijante prema uvjetu minimalne mase.
Druga faza projektiranja obuhvaća direktni proračun čvrstoće metodom konačnih elemenata (MKE). Analizirani su strukturni odzivi te je provedena analiza podobnosti prema Tsai-Wu kriteriju loma laminata. Konstrukcijski elementi koji ne zadovoljavaju kriterij su redimenzionirani. Naposljetku provedena je kontrola izvijanja pojedinih elemenata konstrukcije.The objective of this thesis is the structural design of composite passenger catamaran, designed by „iCat“ company.
The design is carried out through two phases. In the first phase, three design variants were developed. The elements of plating and framing were designed according to the rules of the Croatian Register of Shipping (CRS). Then, a local strength check was performed using the ComposeIT software from the Bureau Veritas (BV) classification society. After that follows comparison of results and selection of the most favorable design variant based on minimum mass criteria.
The second phase of the design includes direct calculation of strength using finite element method (FEM). Structural responses were analyzed and a structural adequacy criterion was carried out based on the Tsai-Wu laminate failure criterion. Structural elements that do not satisfy criterion are redesigned. Finally, a buckling check of individual structural elements was
performed
Numerical analysis of fracture behavior in structural acrylic adhesive
No full textOvaj rad bavi se istraživanjem adhezivnih svojstava strukturno-termalnog akrilnog ljepila u svrhu
razvoja numeričkog modela za simuliranje istog. Kako bi uspješno razvili model za modeliranje
odziva konstrukcije prilikom DCB (eng. Double Cantilever Beam) testa, potrebno je
eksperimentalno odrediti parametar energije loma (eng. Fracture Energy). Za određivanje
energije loma u ovom radu koristit će se dvije metode: SBT (eng. Simple Beam Theory) temeljena
na Euler-Bernoullijevoj teoriji savijanja grede i CBBM (eng. Compliance Based Beam Method)
bazirana na teoriji Timoshenkove grede.
U uvodnom dijelu rada prikazat će se detaljan pregled baterijskih sustava, kemijska osnova ljepila
i njihova primjena u različitim industrijama. Nadalje, poseban naglasak bit će stavljen na teorije
mehanike loma i metode izračuna vrijednosti energije loma.
Nadalje, dat će se uvid u postupak pripreme uzoraka, provedbe eksperimentalnog ispitivanja te
obrade podataka.
Na poslijetku, prikazat će se koraci razvoja numeričkog modela sa svim bitnim postavkama u
softveru Abaqus. Dobiveni rezultati numeričkog modela usporedit će se s eksperimentalno
dobivenim podatcima te će se ocijeniti primjenjivost teorijskih metoda SBT i CBBM na izračun
energije loma.This paper explores the adhesive properties of structural-thermal acrylic adhesive to develop a
numerical model. To successfully create a model for reproducing the structural response during
the Double Cantilever Beam (DCB) test, it is essential to experimentally determine the fracture
energy parameter.
In this study, two methods will be employed to determine the fracture energy: the Simple Beam
Theory (SBT), based on Euler-Bernoulli beam theory, and the Compliance Based Beam Method
(CBBM), grounded in Timoshenko beam theory.
The introductory section will provide a comprehensive review of battery systems, the chemical
background of adhesives, and their applications in various industries. Additionally, an overview
of fracture mechanics will be presented, along with the methods used to calculate fracture energy
values.
Subsequently, the paper will outline the procedures for sample preparation, test execution, and
data processing.
Finally, the steps for creating a numerical model will be demonstrated, including key settings in
the Abaqus software package. The results obtained from the numerical model will be compared
with the experimentally derived data, and the applicability of the theoretical methods, SBT and
CBBM, for calculating fracture energy will be evaluated
Surface modification of cobalt-chromium based implant materials
No full textPotreba za razvojem implantne tehnologije sve se više javlja zbog porasta broja starije populacije koja je sklona oštećenjima koštanih tkiva. Implantni materijali moraju biti sposobni imitirati strukturu i mehanička svojstva tkiva, organa ili kosti kako bi implantati u konačnici uspješno nadomjestili funkciju strukture za zamjenu. No, ugradnjom metalnih implantnih materijala u agresivni okoliš ljudskog tijela može doći do korozije (degradacije) materijala te je stoga važno istražiti korozijsku otpornost istih. Legura na bazi kobalt-krom-molibdena (CoCrMo) koristi se za izradu ortopedskih implantata zbog svojih superiornih mehaničkih svojstava i dobre korozijske otpornosti, ali ista nije bioaktivna. Stoga se u ovom radu, modifikacijom površine legure stvaranjem prevlake na bazi kalcijevih fosfata (CaP), nastoje povećati korozijska otpornost i stupanj bioaktivnosti. Formiranjem CaP prevlake na površini CoCrMo legure kombiniraju se mehanička svojstva metalne legure sa osteokonduktivnim svojstvima kalcijevih fosfata. Modifikacija površine CoCrMo legure provedena je metodom elektrodepozicije; uvjeti elektrodepozicije određeni su metodom cikličke voltametrije (CV). Uspješnost formiranja prevlake potvrđena je optičkom mikroskopijom (OM) i infracrvenom spektroskopijom s Fourierovom transformacijom uz prigušenu totalnu refleksiju (ATR – FTIR). Usporedba elektrokemijskog ponašanja nemodificirane CoCrMo legure i CaP modificirane legure provedena je korištenjem izmjeničnih i istosmjernih elektrokemijskih metoda, koje uključuju metodu određivanja polarizacijskog otpora (eng. Linear Polarization Resistance LPR), metodu Tafelove ekstrapolacije i elektrokemijsku impedancijsku spektroskopiju (EIS) provedenu u simuliranoj tjelesnoj tekućini, Hanksovoj otopini u in vitro uvjetima.The need for development of implant technology is rising due to the increasing proportion of the elderly population who are prone to bone tissue damage. Implant materials must be able to imitate the structure and mechanical properties of tissue, organe or bones in order for implants to successfully replace the functionality of wanted structure. However, after the implantation of metallic implant materials into the aggressive environment of the human body, corrosion (degradation) of the material can occur, so the corrosion resistance of metallic implant materials is examined. An alloy based on cobalt-chromium-molybdenum (CoCrMo) is used as an orthopeadic implant due to its superior mechanical properties and good corrosion resistance, but this alloy is not bioactive. Hence, in this work the CaP coating is formed on the surface of CoCrMo alloy in order to increase the corrosion resistance and bioactivity. The formation of CaP coating on the alloy surface combines the mechanical properties of metal alloy with the osteoconductive properties of CaP materials. Surface modificitaion was performed by electrodeposition method with electrodeposition conditions determined by cyclic voltammetry (CV) method. The successful formation of CaP coating was confirmed by optical microscopy (OM) and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). The comparison of electrochemical behaviour of unmodified and CaP modified CoCrMo alloy was performed using ac and dc electrochemical methods, including linear polarization resistance (LPR), Tafel extrapolation method and electrochemical impedance spectroscopy (EIS) performed in simulated body fluid, Hank’s solution under in vitro conditions