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Transactions of Nonferrous Metals Society of China 2016年第6期26卷 1512-1521页

作者： Biljana BOBIC Jelena BAJAT Ilija BOBIC bore jegdic Institute of Chemistry Technology and Metallurgy University of Belgrade Belgrade 11000 Serbia Faculty of Technology and Metallurgy University of Belgrade Belgrade 11000 Serbia "Vinca" Institute of Nuclear Sciences University of Belgrade Belgrade 11000 Serbia

The influence of corrosion on the surface appearance and microstructure of particulate ZA27/SiCp composites was examined after 30 d immersion in a sodium chloride solution with the access of atmospheric oxygen. The composites with different contents of SiC micro-particles were synthesized via compo casting. Microstructural studies by means of optical microscopy （OM） and scanning electron microscopy （SEM） showed that corrosion occurred in the composite matrices, preferentially in regions of the η phase, rich in zinc. The corrosion processes did not affect the silicon carbide particles incorporated in the matrix alloy. According to the results of electrochemical polarization measurements, an increase in the content of SiC particles in the composite matrice has led to the lower corrosion resistance in the composites.

关键词： metal-matrix composites ZA27 alloy corrosion microstructure polarization resistance corrosion rate

Corrosion behaviour of thixoformed and heat-treated ZA27 alloys in NaCl solution

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Transactions of Nonferrous Metals Society of China 2013年第4期23卷 931-941页

作者： Biljana BOBIC Jelena BAJAT Zagorka ACIMOVIC-PAVLOVIC Ilija BOBIC bore jegdic Institute"Gosa" University of BelgradeMilana Rakica 3511000 BelgradeSerbia Faculty of Technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia "Vinca"Institute of Nuclear Sciences University of BelgradeMike Petrovica Alasa 12-1411001 BelgradeSerbia

The influence of corrosion on the microstructure of thixoformed and heat-treated ZA27 alloys was investigated. The microstructure of ZA27 alloy was affected by heat treatment. The process of electrochemical corrosion occurs in both ZA27 alloys through the area of r/phase. According to the results of immersion test and electrochemical measurements, the corrosion rate of the thixoformed ZA27 alloy is at least 50% lower than that of the thixoformed and thermally processed alloy. This indicates the unfavourable influence of applied heat treatment （T4 regime） on the corrosion resistance of the thixoformed ZA27 alloy.

关键词： ZA27 alloy thixoforming corrosion heat treatment microstructure

Synergistic effect of CeCl3 and benzotriazole on corrosion resistance of naturally aged and artificially aged AA2024 aluminium alloy

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Transactions of Nonferrous Metals Society of China 2020年第6期30卷 1478-1490页

作者： bore JEGDIĆ Biljana BOBIĆ Bojana RADOJKOVIĆ Jovanka KOVAČINA Dunja MARUNKIĆ University of Belgrade Institute for ChemistryTechnology and MetallurgyBelgradeSerbia

The corrosion behaviours of naturally aged and artificially aged AA2024 aluminium alloys in 0.5 mol/dm3 NaCl solution in the presence of environmentally friendly corrosion inhibitors of 10 mmol/dm3 CeCl3, 10 mmol/dm3 BTA and the inhibitor mixture (5 mmol/dm3 CeCl3 + 5 mmol/dm3 BTA) were analyzed. The goal of this work was to determine the level of the synergistic effect of the inhibitor mixture and to explain the nature of this effect. Corrosion properties of the inhibitor layer were studied using the electrochemical impedance spectroscopy (EIS), while the resistance to pit formation and pit growth was studied by applying potentiodynamic polarisation tests. The results of scanning electron microscopy (SEM/EDS) showed that the size of pits formed in naturally aged aluminium alloy was smaller than that formed in artificially aged alloy. The synergistic effect of the inhibitor mixture on corrosion properties of naturally aged alloy was observed throughout 96 h, and in later phases of testing of artificially aged alloy. The synergistic effect of the inhibitor mixture was not noticed on pit formation and pit growth.

关键词： aluminium alloy pitting corrosion corrosion inhibitor cerium benzotriazole

Algorithms and Identities for(q, h)-Bernstein Polynomials and(q, h)-Bézier Curves–A Non-Blossoming Approach

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Analysis in Theory and Applications 2016年第4期32卷 373-386页

作者： Ilija jegdic Jungsook Larson Plamen Simeonov Department of Mathematics Texas Southern University Houston TX 77004 USA Department of Mathematics and Statistics University of Houston-DowntownHouston TX 77002 USA

We establish several fundamental identities, including recurrence relations, degree elevation formulas, partition of unity and Marsden identity, for quantum Bernstein bases and quantum Bezier curves. We also develop two term recurrence relations for quantum Bernstein bases and recursive evaluation algorithms for quantum Bezier curves. Our proofs use standard mathematical induction and other elementary techniques.

关键词： Bernstein polynomials Bezier curves Marsden's identity recursive evaluation.