Wyniki 1-4 spośród 4 dla zapytania: authorDesc:"Zdravko PRAUNSEIS"

Determination of the titanium corrosion resistance by nitrogenion implantation for applications in electrical engineering DOI:10.15199/48.2017.06.11

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Introduction The inherent mechanical properties of metallic materials have made them the material of choice for applications in modern electrical engineering, for instance usage for pacemaker casing, protection of electronic circuits and also bimetallic current brining tires [1], and composition elements of individual protection means [2], which operated in the acid environment [3,11,18]. Three alloys - stainless steels, cobalt-chromium alloys and titanium and its alloys - are also the materials used for this type of application. The favorable local-tissue response and the excellent corrosion resistance of titanium and its alloys have promoted their widespread use at the expense of the other two types of metallic materials. Owing to its enhanced fatigue strength the titanium alloy Ti6Al4V was considered as an interesting alternative to the previously used stainless-steel and cobalt-chromium alloys [8]. However, over the long term the presence of vanadium in this alloy may cause problems, even though the vanadium present in the Ti6Al4V alloy is very stable and the release of vanadium ions under normal conditions is always lower than the toxic level. The toxicity of vanadium is well known, and it can be aggravated when an implant is fractured and the material subsequently undergoes fretting [4]. This phenomenon may cause local irritation of the tissues surrounding the material. In order to avoid the potential risks several solutions have been proposed. One solution is to continue to use CP titanium as an alternative to this alloy. However, titanium is not inert when it is incorporated into the acid fluid. Titanium releases metallic ions, which subsequently form corrosion products in the acid fluids [5,6]. This phenomenon is more significant in the case of titanium than with stainless steels and cobalt-chromium alloys [7]. Considerable attention had been paid in the recent past to the surface treatment of these materials in [...]

Evaluation of mechanical properties of soft magnetic materials for axial flux permanent magnet synchronous machines

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Accurate determination of real material mechanical properties is important for safe servicing of energy components. The aim of the paper is systematic experimental approach for determination of mechanical properties of high strenght low alloyed steels and mild carbon steel in the rolling, thickness and width direction. Streszczenie. W artykule przedstawiono metodę eksperymentalnej i systematycznej oceny właściwości mechanicznych stali niskostopowej i niskowęglowej o wysokiej wytrzymałości. Precyzyjne określenie tych parametrów pozwala na zwiększenie bezpieczeństwa użytkowania i serwisowania elementów. (Ocena właściwości mechanicznych miękkich materiałów magnetycznych w maszynach synchronicznych z magnesami trwałymi o strumieniu osiowym). Keywords: soft magnetic materials - mechanical properties - experimental testing. Słowa kluczowe: materiały magnetyczne miękkie, właściwości mechaniczne, test eksperymentalne. Introduction The high strength low alloyed steels (HSLA) grade HT50 and HT80 is widely used for construction of different modern energy components [1]. The mild steel is typically carbon steel, with a comparatively mild amount of carbon (0,16% to 0,3%) and with ferromagnetic properties. Ferromagnetic properties make it ideal for electrical machines and other electrical devices. Due to the non-laminated rotor discs the mild steel is especially applicable to axial flux permanent magnet synchronous machines. Mild steel with high amount of carbon is vulnerable to rust. Where the rust free technology is required the stainless steel over mild[...]

Fracture Testing of Energy Materials for Application in Electrical Engineering DOI:10.15199/48.2019.01.41

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The basic operation topology of Stirling engine is implemented when the engine receives thermal energy and converts it into mechanical movement. Conversion is possible with three different types of Stirling engine, alpha, beta or gamma type. All three types need an external source of thermal energy. It can be provided by different conventional energy sources or renewable energy sources in applications with external combustion. Stirling engine is most often used in micro Combined Heat and Power (μCHP) applications, which are mostly based on renewable energy sources. Versions with mirrors, using solar energy, and versions with external combustion of e.g. biomass, are used. A pressure vessel is a component of Stirling engine as container designed to hold gases or liquids at a pressure substantially different from the ambient pressure. Pressure vessels can be dangerous, and fatal accidents have occurred in the history of their development and operation, thus in present research determination of quality assessment of high strength steel used for pressure vessel design is necessary [1-4]. Pressure vessel of prototype Stirling engine operated under 210 OC as a hot cylinder and it is made by high temperature resistance steel 10CrMo10V5 and welded together with two undermached welds (Fig. 1). In the assessment of pressure vessels as a welded structures the consideration of both strength mismatching and transferability cannot be avoided. In this paper we first review the effects of the mismatch observed in pressure vessel with two welded joints on strength and fracture, and show that the plastic constraint due to strength mismatching plays an important role in fractureinitiation behavior for ductile and brittle cracks which appeared in the pressure vessels [3]. Finally, for all testing of pressure vessel and the steel specimens the standard test procedures were used for determining the weldability and quality assessment of hig[...]

Winding Design of Coreless Stator Axial Flux Permanent Magnet Synchronous Machines

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In this paper, two winding designs of axial flux permanent magnet synchronous machine with ironless stator (AFPMSM) are presented. The main goal of this paper is to present the influence of both winding design and parameters on AFPMSM static characteristics, which are calculated by using an analytical method. Analytically calculated results are verified with both the finite element method and measurements of back electromotive force (EMF). Streszczenie. Dwa projekty uzwojeń maszyny synchronicznej o strumieniu osiowym z magnesami trwałymi i bezrdzeniowym stojanie są prezentowane. Głównym celem pracy jest pokazanie wpływu obu projektów na statyczną charakterystykę maszyny wyznaczaną na drodze analitycznej. Wyniki obliczeń analitycznych weryfikowane są poprzez metodę elementów skończony[...]

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