Affiliation:
1. Slovak Academy of Sciences
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.
Publisher
Trans Tech Publications, Ltd.
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics,General Materials Science
Reference10 articles.
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.
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.
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.
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.