1. Composite materials with a network microstructure of α-Fe areas surrounded by continuous layer of iron phosphate compounds were prepared on the basis of Fe/FePO4 precipitation coated powder. Spherically shaped particles of this powder were compacted and sintered at 912, 930, 980, 1075 and 1130°C for 3 min in air. Sufficiently fast heating rate, rapid formation of a liquid phase and fast cooling suppresses the development of diffusion processes and consequently the formation of Fe-Fe metallic connections. Microscopic observations showed that, after appropriate processing conditions, an even and continuous layer, comprising a mixture of ferrous orthophosphate and iron oxide compounds, was achieved. Sintering at 1130°C and quenching into liquid nitrogen resulted in the formation of a phosphate layer consisting of fine lamellar structure - graftonite. The phase composition of the phosphate layer was correlated with processing conditions. Corrosion resistance of the sintered composites was measured and related to microstructure and processing technique variants. The phosphate layer resulting from sintering at 912 and 930°C is composed of the ferrous orthophosphate and iron oxide compounds. Due to the formation of a eutectic phase during sintering at 980°C and 1075°C and cooling at 50°C/min, the iron phosphate layer consists of solidified eutectic areas with lamellar structure surrounding the iron oxides. Sintering at 1130°C and quenching into water leads to the formation of a coherent adhesive protective layer having a fine lamellar microstructure consisting of Fe3(PO4)2 matrix and long lamellae of wüstite. Sintering at 1130°C and quenching into liquid nitrogen suppresses the precipitation and growth of long needles. The solidified eutectic phase with fine lamellar structure has the same chemical composition as after quenching into water. The corrosion behaviour of the phosphate coated iron material is affected by its compositional structure and by the compactness of the phosphate coating layer. Improvement of corrosion resistance is associated with the formation of a coherent adhesive protective layer during sintering at a high temperature and a high cooling rate, due to the formation of a eutectic phase solidified into a compact layer with a fine lamellar structure. The consequence is the formation of a network structure of the composite material with α-Fe areas surrounded by a continuous layer of solidified fine lamellar eutectic. This work was realized within the frame of the project „Advanced technology of preparing of micro-composite materials for electrotechnics“, which is supported by The Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, from the Structural Funds of EU, the Operational Program “Research and Development” financed through European Regional Development Fund ITMS:26220220105. This work was also supported by the Slovak Research and Development Agency through project APVV-0222-10.EXPERIMENTAL RESULTS CONCLUSIONS Sintered composite materials on the basis of Fe/FePO 4 coated powdersABSTRACT Eva Dudrová 1, Margita Kabátová 1, Renáta Oriňáková 2 1 Institute of Materials Research SAS, Watsonova 47, 040 01 Košice, Slovakia 2 P. J. Šafárik University, Dpt. of Physical Chemistry, Faculty of Science, Moyzesova 11, 041 54 Košice, Slovakia Ferrous phosphate coated iron powder: Water atomised ASC100.29 Höganäs AB iron powder was milled in a Pallmann mill to form a powder with spherical particles. The coating of iron powder was carried out in phosphating solution (acetone and orthophosphoric acid with 1:9 mole ratio), dried at 60°C/2 h in air and calcined at 400°C/3 h in air. The mass fraction of the ferrous phosphate coating on iron particles was ~2.0 %. Compaction and sintering: The powder was cold compacted into cylindrical samples (Φ10x5 mm 3 ) and sintered at 912, 930, 980, 1075 and 1130°C for 3 minutes in air. Heating rate was ~20°C/min and cooling rate ~50°C/min for all specimens sintered at 912-1075°C. The specimens sintered at 1130°C were quenched into water and/or into liquid nitrogen. Testing methods: The surface morphology of coated powder particles and thermally dependent changes in the iron phosphate layer were studied microscopically (Jeol-JSM-7000F coupled with an Energy Dispersive X-ray spectroscopy analyser INCA) and by X-ray diffraction (SEIFERT XRD 3003/PTS difractometer and analyzed by ZDS search-match program with the PDF2 database and TOPAS). Corrosion behaviour: Conventional three-electrode arrangement (Autolab PGSTAT 302N potentiostat, interfaced to a computer) was used for potentiodynamic polarisation experiments in 1 mol/l NaCl solution (pH 5.6). Polarisation curves were obtained by varying the applied potential from -800 mV to +300 mV at a scan rate of 0.1 mV/s. Phase a: 23.5-24 at.% Fe, 16 at.% P, 59-60.5 at.% O (close to the stoichiometry of the Fe 3 (PO 4 ) 2 compound) Phase b: 50-51 at.% Fe, 49-50 at.% O (iron oxides) Phase c: 44 at.% Fe, 5-6 at.% P, 50-51 at.% O (a mixture of ferrous orthophosphate and iron oxides) sintered at 912-1075°C for 3 min in air and cooled at 50°C/min sintered at 1130°C, quenched into liquid nitrogen 25 at.% Fe, 16 at.% P, 59at.% O (graftonite) Potentiodynamic polarisation curves of phosphate coated iron samples in 1 mol/l NaCl solution with pure iron sample as a control: NoSampleE corr (mV)j corr (mA/cm 2 )Corrosion rate (mm/year) 1Fe-477.311.45317.18 2Fe/FePO 4 /912-427.91.9142.880 3Fe/FePO 4 /930-400.31.7082.569 4Fe/FePO 4 /980-397.51.6222.443 5Fe/FePO 4 /1075-385.81.5742.364 6Fe/FePO 4 /1130/water-51.391.4092.114 7Fe/FePO 4 /1130/nitrogen-61.811.4212.132