Authors

1 Mechanical Eng. Dept, University of Technology, Baghdad, Iraq. dribrahem2016@yahoo.com

2 Mechanical Eng. Dept., University of Technology, Baghdad, Iraq. alrabiee2002@yahoo.com

3 Mechanical Eng. Dept. University of Technology, Baghdad, Iraq. alfattal40@yahoo.com

Abstract

This research aims to study the effect of using the anodizing process on the corrosion rate, mechanical properties as well as the fatigue life for aluminum alloy (7075-T73), which is one of the most commonly used aluminum alloy in production of aircrafts, vehicles and ships structures. The anodizing process was employed through using sulfuric acid for time (20) min in a salty atmosphere. The mechanical properties and fatigue life of the AA7075-T73 were obtained before and after the anodizing process. All the results were listed in detailed tables and figures for comparison purpose. Generally, these results showed a decrease in corrosion rate by (155.06%) in comparison with untreated, an increase in hardness by (21.54%) and a slight decrease in fatigue life by (7.7%) due to anodizing for a time of 20 min at the stress level of (σa = 491.10 MPa). It was concluded that this technique could be applied on other aluminum alloys in order to know the magnitude of change in the mechanical characteristics and their fatigue life.

Keywords

 
[1] X. F. Meng, G. Y. Wei, H. L. Ge, Y. Yu, T. Cao and D. Horst, “anodization for 2024 al alloy from sulfuric-citric acid and anticorrosion performance of anodization films,” Int. J. Electrochem. Sci., 8, pp. 10660-10671, 2013.
[2] Y. Guo, G. S. Frankel, “Characterization of trivalent chromium process coating on AA2024-T3,” Surf. Coat. Techno, 206, pp. 3895–3902, 2012.
[3] M. P. Nascimento, R. C. Souza, I. M. Miguel, W. L. Pigatin and H. J. C. Voorwald, “Effects of tungsten carbide thermal spray coating by HP/HVOF and hard chromium electroplating on AISI 4340 high strength steel,” Surf. Coat. Tech., 138, pp. 113-124, 2001.
[4] M. A. S. Torres and H. J. C. Voorwald, “An evaluation of shot peening, residual stress and stress relaxation on the fatigue life of AISI 4340 steel,” Int. J. Fatigue, 24, pp. 877-886, 2002.
[5] F. Snogan, C. Blanc, G. Mankowski and N. Pebere, “Characterization of sealed anodic films on 7050-T74 and 2214 T6 aluminum alloys,” Surf. Coat. Tech., 154, pp. 94-103, 2002.
[6] W. F. Hosford, “Mechanical Behavior of Materials,” Cambridge University Press, 2005.
[7] D. C. Benjamin, A. L. Richard and H. R. David, “Corrosion prevention and control: a program management guide for selecting materials,” AMMTIAC, September 2006.
 [8] L. Hao and B. R, Cheng, “Advantage of constant current density control over constant voltage control in aluminum anodizing,” Metalast Inc., 2001, www. Metalast.com.
[9] A. Camargo and H. Voorwald, “Influence of anodization on the fatigue strength of 7050-T7451 aluminum alloy,” Fatigue and Fracture of Engineering Materials and Structures, 30,   pp. 993–1007, 2007.
[10] M. Shahzad, M. Chaussumier, R. Chieragatti, C. Mabru, and F. Rezai-Aria, “Surface characterization and influence of anodizing process on fatigue life of Al7050 alloy,” Materials and Design, 32, pp. 3328–3335, 2011.
[11] M. Chaussumier, C. Mabru, M. Shahzad, R. Chieragatti, and F. Rezai-Aria, “A predictive fatigue life model for anodized 7050 aluminum alloy,” International journal of Fatigue ,48, pp. 205-221, 2013.
[12] E. Zalnezhad, A. A. D. Sarhan and M. Hamdi, “Investigating the effects of hard anodizing parameters on surface hardness of hard anodized aerospace AL7075-T6 alloy using fuzzy logic approach for fretting fatigue application,” The International Journal of Advanced Manufacturing Technology, Vol. 68, Issue 1-4, pp. 453-464, September 2013.
[13] D. Liu, G. Wei and P. He, “The effect of sealing and trivalent chromium passivating on anodized aluminum,” College of Materials Science and Engineering, China Jiliang University, Hang Zhou, 2016.
[14] M. Hajihashemi, N. Yazdian, M. Ajabshirij and M. A. Asadabad, “The Effect of hard chromium and anodizing coating on fatigue characteristics of  AA 7075-T6 used in aerospace industries,” Journal of Materials Science and Engineering with Advanced Technology, Vol. 12, pp. 39-47, 2016.