Compaction of a number of ceramic nanopowders with specific surface area up to 80 m2/g, including Al2O3, ZrO2, TiO2, MgAl2OX, YSZ, TiN, SiC, LiMn204 has been mastered. At a pressure amplitude of 1.5 GPa, the relative densities of the pressed billets reached high values of the order of 0.70 – 0.80. Subsequent thermal sintering at reduced to (0.5-0.6)Tmelt temperatures synthesized nanostructured ceramics with an average size of crystallites in the range of 50 – 300 nm for different compounds.
MP pressing and subsequent sintering of weakly agglomerated nanopowders, the synthesis of several types of nanostructured oxide ceramics based on Al2O3 and tetragonal YSZ has been worked out, which can find structural applications due to their high hardness, resistance to abrasive wear and corrosion at high temperatures. Ceramics are characterized by almost maximum density. Bending strength of two types of nanoceramics: Al2O3, doped with magnesium, and composite Al2O3 + 2.8YSZ(60wt.%), exceeded 500 MPa over a wide temperature range. The type of fracture of ceramics based on Al2O3 with the addition of Mg, obtained in a scanning electron microscope, demonstrates high density and fine structure.
With the use of MPP weakly agglomerated nanopowders it is mastered the synthesis of nanostructured ceramics based on cerium oxide stabilized with gadolinium, 0.8CeO2+0.2Gd01,5, and cubic stabilized zirconium dioxide 10YSZ, including with reinforcing additives of nanocrystalline Al2O3. Ceramics are characterized by an average crystal size of 100-300 nm at almost maximum density. Functional tests of 10YSZ ceramics samples showed high specific electrolytic characteristics exceeding 1.5 times the properties of such ceramics obtained by traditional technologies. Ceramics 0.8CeO2+0.2Gd01,5 has high microhardness, 12 GPa, and high electrical conductivity, up to 0.09 (Ohm*cm)-1 at 800°C. These materials are promising for applications as a solid electrolyte in solid oxide fuel cells and oxygen pumps. Characteristic structure of ceramics 0.8CeO2+0.2Gd01,5, removed AFM, shown in figure.
The pressing of nanopowders of a number of metals (Al, Cu, Fe) and metal matrix composites based on them with reinforcing particles Al2O3 and SiC was worked out. When pressing the powders heated in vacuum, almost maximum densities of the materials are achieved. In particular, during the pressing of nanoscale powders of partially oxidized (passivated) aluminum, a method for producing a new nanostructured metal-matrix composite Al-Al2O3, which is a matrix of aluminum with uniformly distributed nanoscale oxide particles, has been developed. During the formation of the material, dispersion hardening occurs, characterized by high thermal stability. The microhardness of the material, 2 GPa, is an order of magnitude greater than the hardness of ordinary aluminum, tensile strength at temperatures up to 300°C reaches 200 MPa.
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