C. Huicochea, I. Rosales, I.E. Castañeda, J. Uruchurtu*
Centro de Investigación en Ingeniería y Ciencias Aplicadas – UAEM; Av. Universidad 1001, Col. Chamilpa, 62210 Cuernavaca, Mor; México
Received 11 April 2007; accepted 16 June 2007
Abstract
In the present work, the electrochemical behavior of molybdenum-silica-niobium alloy produced by arc cast technique is presented, keeping silica constant (at 24 wt %), using different niobium concentrations (5, 10, 15 & 20 wt %) as alloying elements. These samples were immersed in an electrochemical solution of 10 % by volume hydrochloric acid. The corrosion behavior was obtained using electrochemical techniques, namely: open circuit potential, polarization curves and electrochemical current noise. The potential behaviour as a function of time allows to determine the activity of the alloy as a function of its content, the polarization technique was used to obtain characteristic electrochemical parameters and the electrochemical current noise the type of attack while comparing them with the corrosion surface morphological features. Surface images showed different corrosion morphologies, being the most attacked the sample without niobium additions. It was found that niobium additions result in a better corrosion resistance when its concentration is increased in the alloy.
Keywords: polarization curves, electrochemical noise, hydrochloric acid, molybdenum, silica, niobium
Texto disponível em PDF
]]> Full text only in PDF format
References
1. J.G. Gonzalez, I. Rosales, M. Casales, S. Serna, L. Martinez, Mat. Sci. and Eng. A 371 (2004) 217-221. [ Links ]
2. I. Rosales, H. Martínez, Mat. Sci. and Eng. A 379 (2004) 245-250.
3. M.K. Meyer, M. Akinc, J. Am. Ceram. Soc. 79 ( 1996) 938-946.
4. M. Akinc, M.K. Meyer, M.J. Kramer, J.A. Thom, J.J. Huebsch, B. Cook, Mater. Sci. and Eng. A 261 (1999) 16.
5. J.H. Schneibel, M.J. Kramer, D.S. Easton, Scripta Material 46 (2002) 217-221.
6. C.T. Liu, J.H. Schneibel, L. Heatherly, “High Temperature Ordered Intermetallic Alloys VIII”, E.P. George, Eds., Mat. Res. Soc. Sym. Proc. (1999) p.552:KK6.2.
7. T.G. Nieh, C.T. Liu, Intermetallics 8 (2001) 885-889.
]]> 8. R. Cottis, S. Turgoose, “Electrochemical Impedance and Noise”. NACE International, Manchester, 1999.9. M.G. Fontana, N.D. Greene, “Corrosion Engineering”. Third Edition; McGraw-Hill, 1987.
*Corresponding author. E-mail address: juch25@uaem.mx
]]>