Document Type : Original Reaearch Article

Authors

• Iman Mohammadi ¹
• Mazdak Izadi ²
• Mohammad Farooghi ³
• Abdollah Afshar ³

¹ Sharif University of Technology, Department of Materials Science and Engineering, Tehran

² Tariat Modares University, Faculty of Engineering, Tehran, Iran

³ Sharif University of Technology, Department of Materials Science and Engineering, Tehran, Iran

Abstract

The aim of this work is to optimize the hardness of anodizing aluminum coating by design of experimental method. Various parameters affect the hardness of these coatings among which time, temperature and pulse current parameters (current density limit, frequency and duty cycle) were considered. According to this, mentioned parameters in different levels were considered as input variables. Also, the effect of parameters on the hardness of anodizing aluminum coating was obtained as a mathematical model. The final model was achieved by Analysis of variance which was used for attaining the best method to predict the maximum hardness of these coatings. The most effective variables and optimized hardness of anodizing aluminum coating were obtained by using the mathematical model. Experimental
results showed that temperature and quadratic behavior of duty cycle were the most important terms on the hardness of
these coatings. Furthermore, the maximum hardness of this coating was 491Hv, which was attained at the maximum
and minimum current densities of 4.09, 1.23 A/dm2 , frequency of 146.94 Hz, time of 29.50 min, duty cycle of 65.16%
and the bath temperature of 3.13o C.

Keywords

• anodizing
• pulse current
• hardness
• design of experimental