Effect of Chromium on Magnetic Characteristics of Powder Processed Fe-0.35wt%P Alloy
- 1 Metallurgical and Materials Engineering Department Indian Institute of Technology, Roorkee 247667, India
- 2 Metallurgical and Materials Engineering Department Indian Institute of Technology, Roorkee 247667, India
- 3 Metallurgical and Materials Engineering Department Indian Institute of Technology, Roorkee 247667, India
Abstract
The present investigation deals with hot powder preform forging technique for the development of high density iron-phosphorus based alloys. These alloys are known for hot-shortness and are therefore not considered suitable for high temperature working. To remove this problem proper soaking at high temperature to eliminate iron- phosphide eutectic and bring entire phosphorus into solution in iron was aimed. Attempting hot forging thereafter completely eliminates hot as well as cold shortness and thereby helps to form these alloys into very thin sheets. It has also been possible to eliminate the use of costly hydrogen atmosphere during sintering by use of addition of carbon as a reducing agent to form CO gas within the compact by reacting with oxygen of iron powder particles. The glassy ceramic coating applied over the compact serves as a protective coating to avoid atmospheric oxygen attack over the compact held at high temperature. Combined application of carbon and glassy ceramic coating has lead to economy in P/M processing for soft magnetic applications. Fe- 0.07C- 0.3O- 0.35wt% P- 0.35wt% Cr alloy so formed yielded coercivity as low as 0.42 Oe, resistivity as high as 21.8 μcm and total loss as low as 0.170 W/Kg. Such a combination of properties may suit their application in magnetic relays and transformer cores.
- Panasyuk, O.A., and Radomysel’skii, I.D., 1973, “Effect of phosphorus additions upon the magnetic properties of parts from iron powder.” Institute of materials science, Academy of Sciences of the Ukrainian SSR, Vol. 123, pp. 23-26.
- Das, J., Chandra, K., Misra, P.S., and Sarma, B., 2008, “Novel powder metallurgy technique for development of iron-phosphorus based soft magnetic materials.” J. Magn. Magn. Mater, Vol. 320, pp. 906-915.
- Block, H., Cierpisz, C., and Weglinski, B., 1992, “Soft magnetic powder composites for magnetic cores of electrical equipment.” Proceedings of conference on Powder metallurgy materials featuring specific physical properties, Paris, France, pp. 17-1 to 17-6.
- Chandra, K., and Misra, P.S., 2001, “Characteristics of sintered Fe-P alloys.” Proceedings of National Seminar on Advances in Materials & Processing, IIT Roorkee, India, pp. 263-268.
- Narasimhan, K.S., 2004, “P/M processing of soft magnetic materials.” Int J Powder Metall. Vol. 40, pp. 25-36.
- Antonio, D.A. De. 2003, “Soft magnetic ferritic stainless steels.” Adv. Mater. Process. Vol. 161, pp. 29-32.
- Lindskog, P., Tenzelius, J., and Kvist, S.A., 1977, “Phosphorus as an alloying element in Ferrous P/M.” Report PM 76-2. H?gan?s AB, S-263 01 Hoganas, Sweden, pp 1-31.
- Moyer, K.H., 1998, “Magnetic materials and properties for part applications.” ASM Hand Book on Powder Metallurgy & Application, Vol. 7, pp. 1006–1019.
- Chandra, K., 2002, “Development of iron–phosphorus based soft magnetic materials by P/M route.” Ph.D. Thesis, Indian Institute Of Technology Roorkee, Roorkee, India.
- Jones, P., Golder, K.B., Lawcock, R., and Shivanath, R., 1997, “Densification strategies for high endurance P/M components.” Int. J. Powder Metall. Vol. 33, pp. 37- 44.
- Misra, P.S., and Chandra, K., 2010, “High Temperature Oxidation Resistant Glassy Coating.” Indian Patent application no. 153/DEL/2010 dated January 27, 2010.
- Balasubramaniam, R., 2000, “On the corrosion resistance of Delhi iron pillar.” Corrosion Science. Vol. 4, pp. 2103-2129.
- Weglinski, B., and Kaczmar, J., 1980, “Effect of Fe 3 P Addition on Magnetic Properties of Sintered Iron.” Powder Metall. Vol. 23, pp. 210-216.