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The paper presents the method of preparation YAG:Ce precursor powder with ability for synthesis at lower temperature. Mechanochemical processing of an initial powder mixture was used as a preliminary step for subsequent high-temperature treatment of the precursor. The specific surface area, phase composition and luminescence properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. It has been shown that YAG structure formed at lower temperature by 300• C in comparison to the reference specimen but luminescence intesity was dependant on temperature of powder synthesis. The highest luminescence intensity was observed for powders synthesised at 1650• C. Keywords: mechanochemical processing, phosphor, YAG:Ce garnet W artykule przedstawiono otrzymywanie proszku granatu YAG:Ce z zastosowaniem zmodyfikowanej metody reakcji w stanie stałym. Mieszanina proszków wyjściowych została poddana procesowi aktywacji mechanochemicznej celem zwiększenia jego reaktywności podczas syntezy wysokotemperaturowej. Zbadano wpływ aktywacji na powierzchnię właściwą wyjściowej mieszaniny proszków. Proszek wygrzewany w różnych temperaturach został poddany analizie fazowej (XRD) oraz obserwacji na mikroskopie skaningowym (SEM). Zbadano niektóre właściwości optyczne: absorpcję i luminescencję przy wzbudzeniu λ=450 nm. Wykazano, że w wyniku aktywacji mechanochemicznej proszku wyjściowego YAG następuje obniżenie temperatury otrzymywania jednofazowego granatu itrowo-glinowego o 300• C, natomiast intensywność luminescencji zależała od temperatury syntezy; najwyższą uzyskano po syntezie w 1650• C.

Aluminium-based hybrid composites are a new class of advanced materials with the potential of satisfying the demands in engineering applications. This paper describes the effects of carbon addition on the formation and properties of AMC with SiC nanoparticles reinforcement. The composites were produced via mechanical alloying followed by hot pressing. Three forms of carbon, graphite (GR), multiwalled carbon nanotubes (CNTs), and, for the first time, glassy carbon (GC), were used for the hybrid composites manufacturing and compared with tribological properties of Al-SiC composite without carbon addition. GC and CNTs enhanced formation of Al-SiC composite particles and resulted in a homogeneous distribution of reinforcing particles. On the other hand, GR addition altered mechanochemical alloying and did not lead to a proper distribution of nanoparticulate SiC reinforcement. Hot pressing technique led to the reaction between Al and carbon as well as SiC particles and caused the formation of Al4C3 and γ-Al2O3. The subsistence of carbon particles in the composites altered the predominant wear mechanisms since the wear reduction and the stabilization of the friction coefficient were observed. GC with simultaneous γ-Al2O3 formation in the hybrid Al-SiC(n)-C composites turned out to be the most effective additive in terms of their tribological behaviour.

The paper presents an attempt to use milled waste of carbon fiber reinforced polymer (rCFRP) laminates as fillers for polyester resin. The obtained polyester-rCFRP composites were tested for technological, mechanical and frictional properties. It was found that the viscosity increased for the compositions containing rCFRP particles in comparison to the neat resin. Flexural strength improved in comparison to the neat resin, but only for the composites filled with a fraction containing particles below 0.2 mm in diameter and a mixed-diameter particles fraction. For composites containing the above-mentioned fractions, a significant reduction in the dynamic friction coefficient and a reduction in wear (the weight loss after friction test) were found. The obtained results indicate the advisability of further research and optimization of this new type of composites in terms of frictional applications.

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