Technical Transactions. Iss. 10

Technical Transactions. Iss. 10

Type: Collection of magazine numbers
Release date

Collection items (18)


Additive manufacturing of titanium with application of cold spray process

Żórawski, Wojciech, Kowalski, Szymon, Mądry, Janusz, Sienicki, Jarosław, Góral, Anna, Makrenek, Medard
Article
2018
Cold spraying is a new technology which can be used in the area of additive manufacturing. This method is suitable for oxygen-sensitive materials, such as titanium. In this paper the microstructure and mechanical properties of cold sprayed titanium deposit were characterized.

Influence of laser treatment on properties of high speed tool

Ulewicz, Robert, Nový, František
Article
2018
The paper presents the results of heat treatment tests of HS6-5-2 high speed steel with laser working in continuous mode. The tests used steel in the delivery state as well as steel after fluid treatment aimed at diffusion enrichment of the surface layer with carbon and nitrogen. The aim of the research is to determine changes in the structure of steel enriched with carbon and nitrogen and then subjected to the impact of the laser beam.

Influence of composition of anti-graffiti coating system used in rolling stock on fire end structure properties

Radziszewska-Wolińska, Jolanta, Milczarek, Danuta, Radek, Norbert, Pasieczyński, Łukasz, Petru, Michal
Article
2018
The paper discusses fire parameters of individual layers of anti-graffiti coating systems proposed for use in rail transport. Modifications and their effect on flammable properties of these coatings have been described. Performed tests included, first of all, parameters such as lateral spread of flame over the surface and heat emission, whose fulfillment proved the most difficult in the previous studies. For this purpose, polyester putties were tested on an epoxy primer. Then, fire parameters for different anti-graffiti systems containing a swelling layer as an additional protective layer were determined.

Microstructure of laser-modified electro-sparking coatings

Pliszka, Izabela, Radek, Norbert, Gądek-Moszczak, Aneta, Dwornicka, Renata, Bronček, Jozef
Article
2018
The article summarizes research on a method used to improve tribological properties. The paper presents possibilities of using laser surface modification by means of EDM. The performed research confirmed that the concentrated laser beam stream can effectively modify the state of the ESD coating layer, WC-Cu and improve their usability. The work aims to assess the properties of coatings after laser treatment, based on the observation of the newly created structure of the material, the measurement of adhesion and microhardness measurement.

Experimental research on electrodischarge drilling of high aspect ratio holes in Ti-6Al-4V alloy

Lipiec, Piotr, Machno, Magdalena, Skoczypiec, Sebastian
Article
2018
The drilling of small cylindrical (D < 1 mm) holes with a high ratio of length to diameter (L/D > 10) in difficult-to-cut materials is significantly beyond mechanical drilling capabilities. Electrodischarge machining (EDM) is a good and cost effective alternative in such situations. The machinability of electrodischarge machined material is determined by its thermal and electrical properties; therefore, the high electrical resistivity, the relatively high melting point and low thermal conductivity of Ti-6Al-4V alloy cause problems during the machining of parts made of this material. In this article, the results of experimental research on electrodischarge microdrilling in Grade 5 Ti-6Al-4V alloy are presented. The influence of various machining parameters (pulse time, discharge voltage, current amplitude, dielectric pressure, electrode-tool rotation speed) on key technological factors such as hole depth, side gap, linear tool wear, mean drilling speed and hole taper angle was analysed.

Simulation of pipeline random response to stray currents effects produced by D.C. traction system

Szymenderski, Jan, Machczyński, Wojciech
Article
2018
The paper presents a method of the simulation of the pipeline potential shift produced by D.C. traction stray currents which are stochastic in character. The calculation model presented is based on the deterministic model used in the earth-return circuit theory combined with the non-deterministic approach based on the Monte Carlo procedure. The model of the equivalent rail with current energization and the concept of superposition allow one to consider more complicated D.C. railway systems using a segmental approximation of the complex railway route and taking into account a number of substations and loads at any location. A locomotive position and a load current are assumed to be independent random variables in the non-deterministic approach. Using simulation program developed random characteristics of a pipeline response e.g. maximum, minimum, median and mean values can be obtained. Hence the pipeline regions more exposed to corrosion risk can be determined.

Modifications of the soft switching system resistant to disturbances in control systems of voltage sources inverters

Rozegnał, Bartosz, Szular, Zbigniew, Mazgaj, Witold
Article
2018
Reduction of the switching losses in three-phase voltage source inverters can be achieved by using of soft switching systems that not only increase the efficiency of the inverters, but they also reduce the size of the semiconductor cooling circuits, that is especially important in traction vehicles. The majority of existing soft switching systems have some drawbacks that could be danger for inverter operation in the case of disturbances in control systems. The paper briefly describes the structure, operation principles and results of laboratory tests of the proposed soft switching system. Particular attention has been paid to the specific features of alternative versions of the proposed soft switching system, that allow to improve operating parameters of the basic system.

High-frequency cascade converter for a dual-system locomotive

Mazur, Wojciech, Zając-Domański, Waldemar
Article
2018
This article presents the concept for using an LLC resonant converter equipped with a medium-frequency transformer to upgrade the existing EU 07 locomotive into a dual-system vehicle. The work was created which sets out the specification for such an upgrade, but the design was eventually rejected by the investor and it became the subject of a diploma thesis.

Selecting quasi-constant weight code parameters for systems of automatics

Gutenko, Denys
Article
2018
In this paper, the requirements of quasi-constant weight code parameters are considered for a certain number of encoded messages and for various requirements of noise immunity. An algorithm is proposed for choosing the optimal parameters of a quasi-constant weight code for a given number of encoded messages and a level of noise immunity that would ensure maximum speed of control command transmission.

Modeling of contact wire’s de-iceing phenomena using artificial neural networks

Dudzik, Marek, Trębacz, Paweł, Hudym, Vasyl
Article
2018
The article presents results of iced wire’s temperature approximation during process of heating this wire to melt ice. This approximation was implemented in Matlab using a two-layer feedforward artificial neural network (ANN). The results of the approximation are acceptable, but it is possible to improve them.