Multi Objective Optimization of Pitting Corrosion Rate of Micro Plasma Arc Welded Titanium (Ti-6Al-4V) Alloy Sheets using TOPSIS
Keywords:
Pulsed Current, Micro Plasma Arc Welding, Titanium (Ti-6Al-4V), Pitting Corrosion, Linear Polarization, Tafel Plot, TOPSISAbstract
Titanium is having good anti-corrosion properties in both basic and acidic medium. However, when it is subjected to severe heating processing like welding, there is a possibility of corrosion formation at the weld joint. In the present work pulsed current MPAW is used for joining 0.5 mm thick Titanium (Ti-6Al-4V) alloy sheets. Peak Current, Base Current, Pulse Rate and Pulse Width are considered as input parameters and fusion zone corrosion rate is considered as output response. Four factors and five levels are considered. Taguchi L25 orthogonal matrix is adopted and 25 experiments are performed. Linear Polarization method is adopted and corrosion rates are measured from Tafel plots for three different mediums namely 0.5N NaOH, 3.5N NaCl and 0.5N HCl. Empirical mathematical models are developed using statistical software (MINITAB). Analysis of Variance (ANOVA) is carried out at 95% confidence level. Effects of welding parameters on corrosion rate are studied. Multi objective optimization of corrosion rate for the three mediums was carried out using TOPSIS (Technique for Order Preference by Similarly to Ideal Solution).
References
2. Almanza E, Pérez MJ, Rodríguez NA. Corrosion resistance of Ti-6Al-4V and ASTM F75 alloys processed by electron beam melting. Journal of Material Research & Technology 2017; 6(3): 251-257.
3. Zhu Y, Li C, Zhang L. Effects of Cryo-Treatment on Corrosion Behavior and Mechanical Properties of Laser-Welded Commercial Pure Titanium. Materials Transactions 2014; 55(3); 511- 516.
4. Robert P. Houser , Performance of Eleven Ti Alloys in High Temperature, High Pressure Brine Solution, Proceedings World Geothermal Congress 2010 Bali, Indonesia, 25-29 April 2010, pp.1-5.
5. Nava-Dino CG, Lopez-Melendez C, Bautista RG. Corro sion Behavior of Ti-6Al-4V Alloys. Int J Electrochem Sci 2012; 7: 2389-2402.
6. Hajisafari M, Bidaki AZ. Yazdani S. Fatigue and Corros ion Fatigue Properties of Ti-6Al-4V Implant Grade Titanium Alloy in Ringer Solution. Journal of Advanced Materials and Processing 2017; 5(3): 12-22.
7. Prasad KS, Rao Ch.S, Rao DN. Effect of welding param eters on pitting corrosion rate in 3.5N Nacl of Pulsed Current Micro Plasma Arc Welded AISI 304L sheets. Journal of Manufacturing science and production 2013; 13(1&2): 15-23.
8. Kondapalli SP, Ch. Srinivasa Rao, Nageswara Rao D. Optimization of pulsed current parameters to minimize pitting corrosion in Pulsed Current Micro Plasma Arc Welded AISI 304L sheets using Genetic Algorithm, International Journal of Lean Thinking 2013; 4(1): 9-19.
9. Alonso-Falleiros N, Wolynec S. Correlation between Corrosion Potential and Pitting Potential for AISI 304L Austenitic Stainless Steel in 3.5% NaCl Aqueous Solution. Materials Resaerch 2002; 5(1): 77-84.
10. Tsaneva B, Fachikov L, Marcheva Y. Corrosion of Chromium Manganese-Nitrogen Steels In Chloride Media. Journal of the University of Chemical Technol ogy and Metallurgy 2007; 42(2): 163-168.
11. Fauvet P, Balbaud R, Robin Q etal. Corrosion mechan isms of austenitic stainless steels in nitric media used in reprocessing plants. Journal of Nuclear Materials 2008; 375: 52–64.
12. Hwang CL, Yoon K. Multiple Attribute Decision Making. Springer-Verlag, Berlin, 1981.
13. Behzadian M, Khanmohammadi Otaghsara S, Yazdani M. A state-of the-art survey of TOPSIS applications. Expert Systems with Applications 2012; 39(17): 1305 1-13069. 1
4. Chen MF, Tzeng GH. Combining grey relation and TOPSIS concepts for selecting an expatriate host country Mathematical and Computer Modeling 2004; 40(13): 1473-1490.
