IJISET - International Journal of Innovative Science, Engineering & Technology, Vol. 2 Issue 1, January 2015. www.ijiset.com ISSN 2348 – 7968 Corrosion Behavior of V 2 AlC in Different Media Dr. Rana A. Anaee and Dr. Ahmed M. Al-Ghaban Assistant Prof., Materials Engineering Department, University of Technology Baghdad, 10066, Iraq Abstract This work involves studying corrosion behavior of manufactured V 2 AlC by Potentiostat to estimate corrosion resistance in different media include 0.01N of HCl, H 2 SO 4 , NaCl and NaOH over temperatures range of 303–333 K. Polarization resistance values which calculated by Stern-Geary equation indicated that V 2 AlC has the highest resistance in basic medium, while the lowest resistances were in acidic media. Activation energy has been calculated between 303 and 323 K, and the results indicate that the highest energy was in basic medium. The later result was good agreement with the result of corrosion resistance. Keywords: MAX phase materials, Corrosion behavior, V 2 AlC. 1. Introduction From simple commodities to advanced technology, ceramics and metals are the most common materials being used, despite the fact that the two of them have almost opposite properties. Ceramics are good insulators, have good corrosion resistance, but are extremely brittle. On the other hand, metals are known as good electrical and thermal conductors, machinable, have high elastic moduli, but frequently show poor corrosion resistance. The search for materials which have the combination of both metal and ceramic properties is becoming more important in the 21 st century. Transition Metal Carbides and Nitrides, developed by Jeitschko and Nowotny in 1960’s, are ceramics which also have metal properties [1]. This new class of materials is called the MAX phases because of its compositions, where M stands for an early transition metal, A is an A-group element (mostly 13 or 14) and X is either C and/or N. MAX phases are a good electrical and thermal conductors, machinable, and exhibit good corrosion resistance. They have high elastic moduli, good damage tolerance, and excellent thermal shock resistance [2]. Many authors were interested fabrication of V 2 AlC and studied of some their physical and mechanical properties. Zhimei et al. [3] performed theoretical studies of the bulk modulus of M 2 AlC, where M 5 Ti, V, Cr by means of ab initio total energy calculations using the projector augmented wave methods. The bulk modulus of M 2 AlC increases as Ti is substituted with V and Cr by 19% and 36%, respectively. This can be understood since the substitution of Ti by V and Cr is associated with an extensive increase in the M–Al and M–C bond energy. Hettinger et al. [4] investigated the electronic, magnetotransport, thermoelectric, thermal, and elastic properties of four M 2 AlC phases: Ti 2 AlC, V 2 AlC, Cr 2 AlC and Nb 2 AlC. The electrical conductivity, Hall coefficient, and magneto-resistances are analyzed within a two-band framework assuming a temperature-independent charge carrier concentration. With room temperature thermal conductivities in the 25 W/m K range - 45 W/m K for V 2 AlC, they are also good thermal conductors. Yanchun et al. [5] synthesized new layered compounds, (V 0.5 Cr 0.5 ) 3 AlC 2 , (V 0.5 Cr 0.5 ) 4 AlC 3 , and (V 0.5 Cr 0.5 ) 5 Al 2 C 3 by reactive hot pressing V, Cr, Al, and graphite powders. The crystal structures of these new phases were determined using a combination of X-ray diffraction and scanning transmission electron microscopy. Chunfeng et al. [6] studied mechanical properties of V 2 AlC such as flexural strength, fracture toughness and compressive strength. Also, they showed that V 2 AlC could retain a high degree of Young's modulus up to 1200°C. Below 800°C, V2AlC showed excellent thermal shock resistance. Darwin et al. [7] studied the influence of deposition temperature on phase formation of V 2 AlC by magnetron sputtering from elemental targets. While Z.J. Yang et al. [8] studied electronic and phononic properties of V 2 AlC. The aim of present work is fabricate the V 2 AlC by powder metallurgy and its corrosion behavior in different media with 0.01N concentration at four temperatures 303, 313, 323 and 333K. 2. Experimental Part To fabricate the V 2 AlC sample, V, C and Al powders (99% pure) were mixed in stoichiometric proportions, ball milled (BAIRD & TATLOCK) for 20 min at high level of speed for each sample, cold pressed using the hydraulic press machine type (Mega 50 Ton Max) and placed in a graphite die in a vacuum hot press (MTI Corporation GLS 1500X). The latter was evacuated and heated to 1100- 652