中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 22 No. 4 April 2012 |
welds immersed in NaCl solutions
（1. Department of Mechanical Engineering, Sri Ramanujar Engineering College,
Vandalur, Chennai - 600 048, Tamil Nadu, India;
2. Department of Mechanical Engineering, College of Engineering, Guindy,
Anna University, Chennai - 600 025, Tamil Nadu, India;
3. Center for Materials Joining & Research (CEMAJOR), Department of Manufacturing Engineering,
Annamalai University, Annamalainagar - 608 002, Chidambaram, Tamil Nadu, India）
Abstract:The extruded AZ61A magnesium alloy plates of 6 mm thickness were butt welded using friction stir welding (FSW) process. The corrosion behavior of the welds was evaluated by conducting immersion test in NaCl solution at different pH value, immersion time and chloride ion concentrations. An empirical relationship was established incorporating pH value, immersion time and chloride ion concentration to predict the corrosion rate of friction stir welds of AZ61A magnesium alloy at 95% confidence level. Three-factor, five-level central composite rotatable design was used to minimize the number of experimental conditions. Response surface method was used to develop the relationship. The results show that the corrosion resistance of AZ61A magnesium alloy welds in the alkaline solution is better than that in the acidic and neutral solutions, moreover, low corrosion rate is found at low concentrated solution and longer exposure time, and the corrosion morphology is predominantly influenced by the distribution of β-phase.
Key words: magnesium alloy; immersion corrosion; friction stir welding
