Vojnotehnicki glasnik / Military Technical Courier

7-22

Authors: Mrdak Mihailo R.

Plasma spray coatings play an important role in the design of surface properties of engineering components in order to increase their durability and performance under different operating conditions. Coatings are the most often used for wear resistance. This paper presents the microstructure and mechanical properties Al2O3 40wt.%TiO2 coating resistant to dry friction slide, grain abrasion and erosion of particles at operating temperatures up to 540°C. In order to obtain the optimal characteristics of coating was performed optimization of deposition parameters. The powder Al2O340wt.%TiO2 is deposited atmospheric plasma spraying (APS) process with a plasma current of 700, 800 and 900A. Evaluate the quality of the coating Al2O3- 40wt.%TiO2 were made on the basis of their hardness, tensile bond strength and microstructure. The best performance showed the deposited layers with 900A. The morphology of the powder particles Al2O340wt.%TiO2 was examined with SEM (Scanning Electron Microscope). Microstructure of the coatings was examined by light microscopy. Analysis of the deposited layers was performed in accordance with standard Pratt & Whitney. Evaluation of mechanical properties of the layers was done by examining HV0.3 microhardness and tensile strength of the tensile testing. Studies have shown that plasma currents significantly affects the mechanical properties and microstructure of coatings which are of crucial importance for the protection for components subjected to wear.

42-57

Authors: Vesić Nenad O., Simjanović Dušan J.

An application of differential geometry in hiding text-data is presented in this paper. This application is a generalization of similar previously presented methods. Matrix valued functions of more than one variable are used in text hiding. This method is covered by the corresponding programs in the MATHEMATICA software package and compared with the previously presented method.

74-88

Authors: Munić Nenad V., Kovačević Aleksandar M.

In accordance with SORS 1029/89 and SORS 1762/89 military standards, electromagnetic compatibility tests of equipment and weapon systems and military equipment of the Serbian Army are carried out in a Faraday cage. A Faraday cage has many parasitic resonances due to the reflective walls, floor, and ceiling. In order to improve electromagnetic compatibility tests, a complete Faraday cage was modeled. Various imperfections of the cage were detected by comparing the results of simulations and experiments, and they were included into the model.

112-129

Authors: Jocanović Mitar T., Karanović Velibor V., Ivanišević Andrea V., Knežević Darko M.

Hydraulic systems of mobile machines are often contaminated by solid particles. Solid particles increase the abrasive wear intensity of hydraulic components and present one of the main causes of system failure. The paper presents a representative example of the solid particle influence on the wear intensity of hydraulic hammer parts, in the cement industry environment.

141-166

Authors: Milićević Milić R., Milenkov Marjan A.

This paper presents possible ways for determining criteria weights based on the criteria ranks. The linear weights with a variable slope, reciprocal weights, rank order centroid weights, rank sum weights, geometric weights and rank order distribution weights are shown in this paper. When the ranking process involves several experts, there is a possibility for aggregating criteria ranks (weights) using selected mathematical methods, social choice theory methods and the Kemeni median. The application of the selected methods is illustrated with one numerical example and the obtained results are analyzed. The main aim of this paper is a systematic review of possible ways for determining the criteria weights based on criteria ranks given by one or more experts.

194-198

Authors: Golodjaev Aleksandr Ivanovič

This article is about the latest explosive devices, not secret ones, since patents are public. Nowadays there are hydrides of various metal and alloys, capable of bonding and releasing hydrogen. Under certain conditions, the release process is of an avalanche type and occurs in a form of a 'physical' explosion. The paper deals with the method of providing conditions for the avalanche-type release. The method of obtaining necessary parameters of hydrides is described as well as the tendencies in the development of explosive devices.

212-220

Authors: Stopić Srećko R.

From June 23 - 26, 2013, the GDMB Society for Mining, Metallurgy, Resource and Environmental Technology organized 7th European Metallurgical Conference (EMC 2013) in Weimar, Germany. The previous European metallurgical conferences were organized by the GDMB in Friedrichshafen (2001), Hanover (2003), Leipzig (2005), Duesseldorf (2007), Innsbruck (2009), and Duesseldorf (2011). The GDMB is a non-profit organization from Clausthal, Germany, focused on combining science with practical experience in metallurgy, mining, materials engineering, mineral processing, recycling and refining of metals, and manufacturing of semi- and finishing products. The European Metallurgical conference EMC is one of the most well-known conferences worldwide in the field of non-ferrous metallurgy and is attended regularly by decision makers from industry and universities. The scientific program contained 6 plenary lectures and more than 130 presentations. An extensive poster exhibition was held, during which the authors had an opportunity to introduce their posters to the entire plenum as a part of a brief presentation., The € 500 worth 'Poster Award EMC 2011 was awarded to Christoph Pichler from the Montan-University in Leoben, Austria. Not only the most important European countries were represented here, but also more than one third of the lecturers were from countries outside Europe (Canada, Japan, China, USA, South Africa, Australia). The origin of the participants reflects the aim of the organizers: to make this conference a worldwide platform for the scientific exchange of experience and information. The scientific presentations of the conference are presented in Proceedings: Vol. 1: Copper, Precious Metals, Waste effluents Treatment/ Biohydrometallurgical applications; Process Metallurgy, Bridging Non- Ferrous and Ferrous Metallurgy; Vol. 2: Lead and Zinc, Light metals, Sustainable technologies, Sustainable of non-ferrous metals production, Process Control/Process Modelling, Waste heat recovery by ORC Power Generation Vol. 3: General Hydrometallurgy, General Pyrometallurgy, Vessel Integrity, Process Gas Treatment; Recycling The plenary lectures will be published in the scientific journal 'World of Metallurgy - ERZMETALL', published by GDMB. The next 8th European Metallurgical Conference will be held between June 14 and June 17, 2015 in Duesseldorf.