An Experimental Study of Sintered (Ni-Cr-xAl2O3) Composites

  • Alaa Abdulhasan Atiyah Assistant Professor, University of Technology -Baghdad
Keywords: Metal matrix composites, (Ni-Cr-xAl2O3) composite, Thermal analysis and Corrosion in seawater.


This paper deals with the (Ni-Cr- xAl2O3) metallic composites (MCCs). Restraining of of thermal expansion at adequate mechanical and corrosion properties is the main objective of this work. Composites are fabricated with four weight percentages of (x = 1, 2, 5 and 10% Al2O3). Compacting and sintering has accomplished at (636 MPa) and 1250oC for 7 hrs. All sintered compacts were examined for phases and microstructure featuring. Results have indicated, the incorporation of Al2O3 with the matrix is due to the efficient sintering conditions, that diminishing the grain growth and increasing the softening temperature from 850°C to become 1350°C. Volume expansion appeared in the base sintered composites (NiCr-xAl2O3) due to pores evolution according to SEM observation. As, the Al2O3 has increased, the microhardness and corrosion resistance have improved. DSC results show a clear one exothermic and one endothermic reaction were occurred during the heating cycle. Corrosion behavior of fabricated composites was estimated by polarization curves using Potentiostat at scan rate 3 mV.sec-1. Potential-time measurements showed the formation of protective layer on surface composites compared with Ni-Cr base composite through an obtaining of the nobler open circuit potentials for composites. Corrosion parameters were estimated by the Tafel extrapolation method, these parameters indicated that the corrosion potential shifted toward a positive direction in addition to get lower corrosion current density especially for Ni-Cr/5%Alumina composite.

Author Biography

Alaa Abdulhasan Atiyah, Assistant Professor, University of Technology -Baghdad
Department of Materials Engineering


- R. Asthana, S.T. Mileiko, and N. Sobczak, “Wettability and interface considerations in advanced heat-resistant Ni-base composites”, Bulletin of The Polish Academy of Sciences Technical Sciences, Vol. 54, No. 2, (2006), 147-166.

- José Roberto de Oliveira Bauer, Alessandro Dourado Loguercio, Alessandra Reis and Leonardo Eloy Rodrigues Filho, “Microhardness of Ni-Cr alloys under different casting conditions”, Braz Oral Res, Vol. 20, No. 1, (2006), 40-46.

- C. N. Tharamania and S. M. Mayannaz, “Studies on the Development and Characterization of Ni–Cr Alloys for Fuel Cell Applications”, Electrochemical and Solid-State Letters, Vol.9, No. 9, (2006), A412-A414.

- Viswanathan S. SAJI, Han-Cheol CHOE, “Electrochemical behavior of Co-Cr and Ni-Cr dental cast alloys”, Trans. Nonferrous Met. Soc. China, Vo. 19, (2009), 785-790.

- I. L´opez-B´aez, E. Mart´ınez-Franco, H. Zoz, and L.G. Tr´apaga-Mart´ınez, “Structural evolution of Ni-20Cr alloy during ball milling of elemental powders”, Revista Mexicana De Fisica, Vol.57, No.2, (2011), 176–183.

- Tevfik Yavuz, Aslı Acar, Serhan Akman and Atiye Nilgun Ozturk, “Effect of Surface Treatment on Elemental Composition of Recast NiCr Alloy”, Materials Sciences and Applications, Vol. 3, (2012), 163-167.

- Z. Dong, X. Peng, Y. Guan, L. Li and F. Wang, “Optimization of composition and structure of electrodeposited Ni–Cr composites for increasing the oxidation resistance”, Corrosion Science, Vol. 62, (2012), 147–152.

- Mykolas Gladkovas et al., Corrosion study of electroplated nickel MMC with B4C,Al2O3 & SiC, Institute of Chemistry,Lithuania.

- J.F. Flores, et al., Corrosion and Erosion-Corrosion Processes of Metal-Matrix Composites in Slurry Conditions, ASM International, JMEPEG (2012) 21:395–405.

- L.L. Sousa, J.W.J. Silva, N.A.S. Sampaio, R.Z.Nakazato, H.A. Acciari, E.N. Codaro; “Corrosion process development of a Ni-Cr-Mo alloy used in dental prosthesis”;International Journal of Engineering Research and Development e-ISSN: 2278-067X, p-ISSN: 2278-800X, Volume 10, Issue 3 (March 2014), PP.70-76.

- Feng-Jiao Liu, Ming-Hao Fang, Zhao-Hui Huang, Yan-Gai Liu, Sai-Fang Huang, Xin Min, Mei-Ling Hu, and Hai-Peng Ji, “Preparation and mechanical properties of NiCr–Al2O3–ZrO2(8Y) ceramic composites”, Materials Science and Engineering, Vol. A 554, (2012), 1– 5.

- Saidatulakmar Shamsuddin, Shamsul Baharin Jamaludin, Zuhailawati Hussain and Zainal Arifin Ahmad, “Characterization of Fe-Cr-Al2O3 Composites Fabricated by Powder Metallurgy Method with Varying Weight Percentage of Alumina”, Journal of Physical Science, Vol. 19(1), 89–95, (2008).

- Kedici, S.P., A. Abbas Aksüt, M. Ali Kílíçarslan, G. Bayramoglu, K. Gökdemir, 1998. Corrosion behaviour of dental metals and alloys in different media. Journal of Oral Rehabilitation, 25: 800-808.

- Bumgardner, J.D., L.C. Lucas, 1995. Cellular response to metallic ions released from nickel–chromium dental alloys, J. Dent. Res., 74: 1521-1527.

Articles - archived