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29.03.2024

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Selected properties of ZrB₂ composites obtained by SPS method for parts of electro-erosion shaping machines

Annamaria Naughton-Duszova, Elżbieta Bączek, Marcin Podsiadło

Sintering furnance (a), graphite elements (b), ovenchamber (c)

Sintering furnance (a), graphite elements (b), ovenchamber (c)

The effect of the addition of silicon carbide and boron carbide powders on the properties of ZrB2 ceramic composites constituting UHTC materials (ultra high temperature ceramics) was investigated. Polycrystalline zirconium boride samples as well as matrix composites of this phase with addition of 2 and 10 wt.% SiC and B4C were obtained by pressure-assisted sintering using SPS/FAST (spark plasma sintering/field assisted sintering technique) in the temperature range of 1800÷2000°C. Samples were characterized by X-ray diffraction, scanning electron microscopy, hardness and fracture toughness. The obtained materials are characterized by a high relative density in the range of 97÷98%. Higher hardness and fracture toughness were observed for the composite obtained in temperature 1900°C.

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Triangulation methods for effusion holes measurements in combustion chambers of aircraft engines

Piotr Lampa, Mariusz Mrzygłód, Jacek Reiner

Experimental setup with triangulation head

Experimental setup with triangulation head

An important problem of modern aero-engines’ construction is effective cooling of combustor liner attained by effusion holes. The laser-drilled channels are a critical metrological challenge resulting from their small diameter (below 1 mm), irregular shape and angular orientation to the surface. Hence, in this case, the tactile CMM measurement methods are timeconsuming, error-susceptible and hazardous to the measuring stylus. The paper compares two methods of triangulation scanning of the surface of the engine combustion chamber with angular effusion holes (according to normal to surface and coaxially with hole). Additionally, four algorithms for processing measurement data were developed and evaluated, aiming at determination of the position and holes diameter. The paper also discusses the problem of measurement and calculation disturbance.

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Coordinate measuring arms - different methods of points collection

Michał Rak, Eugeniusz Ratajczyk

Aluminum cube (a),teflon cube (b)

Aluminum cube (a),teflon cube (b)

This paper deals with different methods of points collection using coordinate measuring arm. The research is divided into two parts. The first one is about measuring an aluminum cube with different geometric features with the use of hard probe and laser scanner. For the analysis some features and some resulting parameters were applied, like angle between two planes. As the reference, data from CMM measurements is used due to obtain higher level of accuracy of device. In the second part, a Teflon cube was used for the measurement. As this is a softer material than aluminum, measuring force gives significant impact on the results. To verify this, hard and triggering head was used.

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The assessment of the surface texture of friction node components after tribological tests

Stanisław Adamczak, Jacek Świderski, Tomasz Dobrowolski

Isometric image of the ball (Talysurf CCI)

Isometric image of the ball (Talysurf CCI)

At present, a number of methods can be applied to measure the surface structure of elements. In this paper, following methods were selected to measure the surface texture of friction node components (a ball-disc couple) after tribological tests: contact profilometry, coherence correlation interferometry and atomic force microscopy. The specimens under investigation were: a disc coated by DLC (diamond-like carbon) layer and a ball made of bearing steel.

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