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Microstructure development of TiB₂-Cu nanocomposite powders during cold and detonation spraying was investigated. The powders were produced by self-propagating high-temperature synthesis (SHS) followed by mechanical milling. A computer model was developed to calculate the temperatures during detonation spraying. The change in the nanostructure of the powders during spraying was studied: due to low temperatures in cold spraying the size of TiB₂ particles in the coatings was well retained, in detonation sprayed coatings the growth of the particles was observed, the mode of spraying affecting the microstructure and the size of the particles.

The effect of BN addition on hydrogen uptake by Ti after and during mechanochemical activation under flow conditions was studied using kinetic, structural, microscopic and spectroscopic techniques. An addition of hexagonal BN significantly stimulated Ti-H₂ interaction during and after the milling process. The hydrogen uptake temperature (T_max) decreased from 960 to 590 K after mechanical treatment of Ti with h-BN in helium flow due to formation of porous BN matrix containing randomly distributed Ti nanofragments. No titanium surface or bulk modification by N (B) atoms was found. Contrary to this, new types of occupation sites available for hydrogen in Ti lattice were formed under the milling in H₂/He flow. These centres responsible for a drastic reduction of H₂ desorption temperature from 1000 to 670-610 K were attributed to the presence of interstitial N atoms. Similar effect on hydrogen distribution between the site types was observed for TiH₂/h-BN as-milled system.

A methodological approach is presented to study gas-solid interactions under mechanochemical activation. Based on a detailed analysis of bulk microstructure, surface features control of milling energy parameters, the H₂ sorption kinetics in Mg₂Ni/Ni nanostructured powders was studied. Hydriding rate and specific parameters such as turnover frequency, mechanochemical gain and instantaneous yield were used to analyze the process on an absolute scale, to elucidate the reaction mechanism and highlight mechanochemical effects.

Glassy solid electrolytes with higher Li₂S content were mechanochemically prepared in the Li₂S-P₂S₅ based multicomponent system, and showed high conductivity by the addition of glass formers SiS₂ and Al₂S₃. The 78Li₂S ×19.8P₂S₅×1.1SiS₂×1.1Al₂S₃ (mol. %) glass exhibited the conductivity of 1.2×10^-4 S/cm at room temperature, which was twice as high as the conductivity of the 78Li₂S×19.8P₂S₅×2.2SiS₂ glass without Al₂S₃. The glass ceramics obtained by crystallization of the glasses showed the same XRD patterns as superionic crystals called thio-LISICON II phase of Li_4-xGe_1-xP_xS₄, which is one of the best Li⁺ ion conducting crystals with very high conductivity over 10^-3 S/cm at ambient temperature. The conductivity of the glass ceramic prepared by heating the glass at 230 ^oC was 1.2×10^-3 S/cm, which was one order of magnitude higher than that of the corresponding glass. The precipitated thio-LISICON II analogs are responsible for the high conductivity of the glass ceramics.

In this paper, the synthesis of the C₂S cement by using reactive mixture containing fly ash (class F) from fluidized coal combustion and Ca(OH)₂ (CaO/SiO₂ ratio of 2) by mechanochemical treatment and subsequent heating is studied. Changes in structure and phase composition of milled and calcinated products of reactive mixture are compared with those of starting mixture. Two hours milling leads to mechanochemical decomposition of portlandite and to the structural and compositional metastability of mixture. The formation of the new compounds as C₂S precursors (CSH and a-C₂SH gels with low degree of ordering and a- and b-C₂S nanocrystalline phases) was confirmed after 2 h milling by X-ray diffraction and infrared spectroscopy. Creation of a- and b-C₂S and gehlenite in milled reactive mixture takes place at lower temperature (600^oC) compared to non-milled starting mixture (1200^oC). Mechanochemical synthesis in combination with thermal treatment offers opportunities for the increased utilization of coal fly ash as a basic raw material for belite production.

Conventional mechanical alloying (MA) is used to process mixtures of powders and generates a product that is also in powder form. MA can also be adapted to the preparation of coatings. For example, if a plate is attached to the wall of the milling container, the impacts by the milling balls activate the surface of the plate, deliver particles from the powder charge and pound them onto or into the surface. The structure and properties of the coating depend on the milling conditions and the properties of the components. In this paper, some aspects essential to the preparation of coatings are discussed. In particular, the importance of the relative hardness of the components is demonstrated by comparing the deposition of aluminium on steel and nickel on aluminium. Mechanical deposition is a promising method that may be utilized to produce a variety of coatings, but its successful application requires detailed understanding and control of the process.

M₃H(SO₄)₂ (M = Na, K, Rb) crystals, which are known to undergo superprotonic phase transition in the case of M = K and Rb, were prepared via mechanochemical process from equimolar M₂SO₄ and MHSO₄. The phase transitions of M₃H(SO₄)₂ prepared by mechanical milling using a high energy ball mill apparatus were confirmed from DTA-TG and conductivity measurements, although the phase transition temperatures were slightly lower than that of M₃H(SO₄)₂ prepared via solution process. The Rb₃H(SO₄)₂ prepared by mechanical milling showed reproducible ionic conductivity of 1×10^-3 S/cm at 230 ^oC under dry N₂ atmosphere.

Bismuth vanadate (BiVO₄) can be synthesized by mechanochemical reaction between bismuth oxide (Bi₂O₃) and vanadium oxide (V₂O₅) by using a planetary ball mill at ambient temperature. The following solid state reaction takes place mechanochemically during the milling: Bi₂O₃ + V₂O₅ ® 2BiVO₄. The particles of the sample look like agglomerates of fine grains with sizes less than 200 nm, and the agglomerates seem to be consisting of primary particles with several microns. The mechanochemical reaction ratio between Bi₂O₃ and V₂O₅ is saturated around 90 %. Heating treatment above 300^oC leads to the formation of homogeneous BiVO₄ with an increase in reaction ratio up to about 99.4 %. The mechanochemical method enables us to synthesize other bismuth complex oxides (BiAO₄; A = P, Nb and Sb).

We developed a method for narrowing the band gap in an oxide powder such as ZnO by doping other components such as S (sulphur) and N (nitrogen). The method consists of grinding a mixture of ZnO powder and non-metal element in air, followed by heating the milled sample at 400 ^oC. The former enables us to cause mechanochemical reaction between the components, and the latter allows us to enhance the bonding strength, as well as to remove the unreacted starting samples away from the surface of the oxide particles. The temperature has to be chosen in the heating operation so as to avoid any decomposition of the doped sample. The detailed information on doping S and N into ZnO powder, as well as its photo-catalytic reactivity, is shown in this report.

The objective of the present work was to show the beneficial effects of mechanochemical treatment of CuO-Al system for fabrication of composites consisting of Cu(Al) solid solution and Al₂O₃ ceramic with ultrafine grain microstructures. In particular, our research focused on explanation of the mechanism and kinetics of mechanochemically induced reactions in metal oxide-active metal system.