Microstructure of Composites Based on Phosphated Iron Powder

Abstract:

The commercial carbonyl iron powder coated with iron phosphate (20 wt.%) was dried (60°C for 2 h in air), calcinated at 400°C for 3 h in air, compacted at 600 MPa into cylindrical samples and subsequently sintered at 820, 900 and 1110°C for 30 min in N₂-10%H₂ atmosphere. By means of EDX and XRD analyses the phase composition of the coating and sintered microstructure was studied. Microstructure resulting from sintering at 820 and 900°C was formed by initial iron particles surrounded with the crystalline FePO₄ and α-Fe₂O₃ phases. Due to liquid phase sintering at 1110°C a mixed microstructure containing spheroidized α-Fe phase surrounded by solidified liquid phase consisting of iron oxides and phosphorous compounds has been formed. In order to prepare a network composite microstructure the compacts based on spherical iron particles size of 100-160 µm coated with 2 wt.% of iron phosphate were dried, calcined at 400°C, compacted and liquid phase sintered at 980°C.

• Periodical: Materials Science Forum (Volume 782)
• Pages: 495-498
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.782.495
• Online since: April 2014
• Authors: Margita Kabátová*, Eva Dudrová, Helena Bruncková
• Keywords: Iron Phosphated Powder, Phase Composition, Sintered Microstructure

References

[1] T.S.N. Sankara Narayanan, Surface pretreatment by phosphate conversion coatings. A Review, Rev. Adv. Mater. Sci., 9 (2005) 130-177.

[2] B. Panicaud, J. L. Grosseau-Poussard, C. Huvier, S. Rebeyrat, J. F. Dinhut, Chronological study of the oxidation of phosphated α-iron. Mat. Sci. and Eng., A356 (2003) 434-442.

DOI: 10.1016/s0921-5093(03)00157-6

[3] L. Zhang, L. Ghussn, L.M. Schmitt, E.D. Zanotto, R.K. Brow, M.E. Schlesinger, Thermal stability of glasses from the Fe4(P2O7)3–Fe(PO3)3 system, J. Non-Crystalline Solids, 356 (2010) 2965-2968.

DOI: 10.1016/j.jnoncrysol.2010.03.044

[4] J.L. Grosseau-Poussard, B. Panicaud, F. Pedraza, P.O. Renault, J.F. Silvain, Iron oxidation under the influence of phosphate thin films. J. Appl. Physics., 94 (2003) 1 784-778.

DOI: 10.1063/1.1579126

[5] S. Rebeyrat, J.L. Grosseau-Poussard, J.F. Silvain, B. Panicaud, J.F. Dinhut, Phosphating of bulk a-iron and its oxidation resistance at 400°C, Appl. Surf. Sci., 199 (2002) 1-4 11-21.

DOI: 10.1016/s0169-4332(02)00152-6

[6] H. Brunckova, M. Kabatova, E. Dudrova, The effect of iron phosphate, alumina and silica coatings on the morphology of carbonyl iron particles, Surf. Interface Anal., 42 (2010) 13-20.

DOI: 10.1002/sia.3132

[7] H. Liu, P. Li. Lu, Y. Wei, Y. Sun, Transformation of ferrihydrite in the presence or absence of trace Fe(II): The effect of preparation procedures of ferrihydrite. J. Solid State Chem., 182 (2009) 7 1767-1771.

DOI: 10.1016/j.jssc.2009.03.030

[8] S. Scaccia, M. Carewska, P.P. Prosini, Thermoanalytical study of iron(III) phosphate obtained by homogeneous precipitation from different Media. Thermochim. Acta, 413 (2004) 1-2 81-86.

DOI: 10.1016/j.tca.2003.10.024

[9] J. Korinth, P. Royen, Zur Kenntnis der Reduktion von Metallsalzen. I. Reaktionen im System Fe2O3/FePO4, Zeitschrift f. Anorg. und Allg. Chemie, 313 (1961) 3-4 121–137.

DOI: 10.1002/zaac.19613130302

[10] L. Zhang, Phase equilibria in the iron phosphate system, http: /scholarsmine. mst. edu/thesis/Phase equilibria_in_09007dcc80907f7d. html.