Application of the levitation technique for investigation of metal alloys and phase equilibria in slags

Experimental methods, based on electromagnetic levitation, have been developed for preparation and investigation of copper-rich alloys, and for the determination of oxide-metal phase equilibria. These techniques involve high-temperature equilibration, rapid quenching and chemical analysis of the phases using electron probe X-ray microanalysis. The experiments can be carried out in the temperature range 1373-1873 K (= 1100 degrees C-1600 degrees C). A developed calibration method, using phase equilibria data in known oxide systems, was applied for pyrometric temperature measurements. Described methods of the application of the electro-magnetic levitations were used for in-situ formation of Cu-based alloys and for formation of Ca-ferrite slags equilibrated with metallic copper

Transformation of mineral matter during pyrolysis, gasification and combustion of biosolid chars

During thermochemical processing of biosolids in sewage sludge, different forms of phosphorus-containing compounds are generated in biosolid chars (biochars). This study examines the effects of biochar processing conditions on the mineral compounds produced during the pyrolysis, gasification, and combustion of biosolids, and the major determinants of phase formation kinetics. Our results show identified phase transformations through experiments in a laboratory tube furnace followed by X-ray diffraction analysis (XRD). Additionally, a synchrotron powder diffraction study was conducted to verify XRD results of the laboratory processed samples and to observe in situ phase transformations in biochars. It was found that under a neutral atmosphere, crystalline oxide phases are formed at lower temperatures and much faster than iron phosphide, while gasification and combustion conditions led to the formation of crystalline phases in phosphate forms. These forms of phosphorus compounds in by-products of biosolids thermochemical treatment can be used as agricultural fertilizers

Oriented Sm-doped CeO<inf>2</inf> thin films on biaxially textured Ni-W substrate produced by ultrasonic spray deposition

A new method of producing Sm-doped CeO2 thin films on metal substrates using an ultrasonic nebuliser has been developed and experimentally verified. Sm-doped CeO2 films with a thickness down to 50 nm and the required properties were consistently and cost effectively produced on Ni-W textured substrates. High film uniformity and c-axis crystal orientation were confirmed by electron microscopy and X-ray diffraction. Characteristics of films and elements valence states are discussed. Our results suggest that the techniques used are promising for further development of buffer layer formation for textured high-temperature superconducting tape applications

Continuous production of Bi-2212 thick film on silver tape

Bi-2212 thick film on silver tapes are seen as a simple and low cost alternative to high temperature superconducting wires produced by the Powder In Thbe (PIT) technique, particularly in react and wind applications. A rig for the continuous production of Bi-2212 tapes for use in react and wind component manufacture has been developed and commissioned. The rig consists of several sections, each fully automatic, for task specific duties in the production of HTS tape. The major sections are: tape coating, sintering and annealing. High temperature superconducting tapes with engineering critical current densities of 10 kA/cm2 (77 K, self field), and lengths of up to 100 m have been produced using the rig. Properties of the finished tape are discussed and results are presented for current density versus bend radius and applied strain. Depending on tape content and thickness, irreversible strain tirrm varies between 0.04 and 0.1 %. Cyclic bending tests when applied strain does not exceed Eirrm showed negligible reduction in J c along the length of the tape