The corrosion behavior of NiTi alloy and stainless steels (AISI 316L and X2CrNiMoN22-5-3) in 0.9% sodium chloride (0.154 moll-1) solution was investigated using open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Microstructural analyses before and after electrochemical tests were performed with the scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS). The lowest corrosion current density has NiTi alloy and the extent of the passive range increased in the order AISI 316L stainless steel NiTi alloy and X2CrNiMoN22-5-3 duplex stainless steel. The oxide film formed on all samples has a double-layer structure consisting of a barrier-type inner layer and a porous outer layer. Oxide films formed on the surface of steels mainly contains iron oxides and chromium oxide, while the surface film of the NiTi alloy mainly contains TiO2 oxide.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 1600863On the entertainment ''The best scientific achievements in the year 2016'' of the Faculty of Natural Sciences and Engineering, University of Ljubljana, were coworkers of the scientific project in cooperation with foreign partners presented scientific achievement ''Disassembly and recycling waste electrical and electronic equipment''. In the framework of the achievment, a review was performed of disassemby and recycling procedures and technics in the field of Waste Electrical and Electronic Equipment, Components and Devices. A successful study was carried out and presented in detail of the whole process of disassembly of a mobile phone. An analysis was done of the selected components from the disassembly and analysis of printed circuit boards, monitors and mobile phones.
E.01 National awards
COBISS.SI-ID: 165283114. CONFERENCE PAZU was held 25./26. November 2016 in MURSKA REPUBLIKA (Hotel Zvezda) in Murska Sobota. The Conference had three sets: 1) The Plenum with the round table: PAZU Pomurje. 2) Lecture members: work and achievement presentations. 3) Presentation lecture: New members who have joined since the last Conference PAZU, have presented there doctoral thesis. The first day 18 lectures was carried out, on the second day 14. Scientific contributions with natural-science-technical and medical content, are/or will be published in the journal Anali PAZU, scientific contributions with social science and humanistic content however, in the journal Anali PAZU HD. Expert contributions will be published in a professional journal Pomurska obzorja.
B.01 Organiser of a scientific meeting
COBISS.SI-ID: 89456897This doctoral thesis deals with the problem of the influence of the multi-axial stress state at the beginning and end of the superelastic plateau in the Shape Memory Alloy Ni-Ti. For our research work commercially available orthodontic wire Ni-Ti was used with a content of 50,6 at.% Ni. In the first part of the research we determined the characterization of the selected material. We determined the transformation temperatures Ms, Mf, As, Af, modulus of elasticity, stress and strain at the beginning and end of the superelastic plateau, and analysed the microstructure of the output un-deformed state. With in-situ measurement of the electrical resistance during uni-axial loading on the device we simulated a uniaxial stress state, which confirmed the usefulness of this method for determination of the transition into superelastic condition or accompanying the stress-induced martensitic phase transformations. Based on these results, in the second part of the research we developed a device to simulate the multi-axial stress state with the possibility of in-situ measurement of electrical resistance and microhardness. We simulated the bending, torsion and combined torsion and bending loads which are present in orthodontic treatment. The simultaneous measurement of electrical resistance for this multi-axial stress state was defined during the transition into the superelastic area. By analysing the microstructures before and after load changes were identified and an evolution model of microstructure was erected for different stress states.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 273707520Janko Ferčec joined the company Talum d.d. on 5.5.2014. He is employed as Head of Development Projects. In the company, he participates in the research and analysis of aluminium and Al alloys, as well as development of new products manufactured from Al alloys. Recently, he has been the leader of the company's development projects and participates in projects financed from national and European funds.
F.17 Transfer of existing technologies, know-how, methods and procedures into practice