تاثير الحماية من التاكل بواسطة الليزر على سبائك الالمنيوم == The Effect of Laser Surface Melting Corrosion Protection On Al Alloys
Author name:
هبة خميس اسماعيل
Supervisor name:
شذى احمد سامح
General topic:
Chemical Engineering
Specific topic:
Chemical Engineering
Degree:
Master
University:
University of Technology - Department Of Chemical Engineering
Language:
English
University location:
Baghdad
First pages:
38T271 - p.pdf
Abstract:
يهدف هذا البحث الى دراسة تاثير المعاملة بالليزر على تاكل سبائك الالومنيوم (7075, 6061, 5083) المغمورة في محلول ملحي (كلوريد الصوديوم) بمختلف التراكيز. وقد تم اعداد عينات من سبائك الالومنيوم ذات ابعاد (2 ملم) سمك وقطر (25 ملم)، وكانت تجارب الاستقطاب في مح | The objectives of the present project are to generate uniform melted layers, free of large second phases to assess the corrosion resistance of the laser treated surface in comparison with the untreated alloy. So disc samples of (7075, 6061 and 5083) aluminum alloys of 2 mm thickness and 25 mm diameter, have been prepared. Polarization tests were carried out in (M lab potentiostat / galvanostat) (Germany) at 298K temperature and (1.5, 2.5 and 3.5) % wt of NaCl solution. The experiments were carried out before and after laser surface melting by (Nd : YAG, MED - 810) pulse laser, system (Q - Switched Nd : YAG 1064/532nm). Before laser surface melting the results showed that the value of the corrosion current density obviously increases with increasing the concentration of NaCl from 1.5% to 3.5%. As well as higher Cl - ions concentration more negative pitting potential (Epit) of aluminum alloys and decrease in the electrochemical stability of aluminum. The corrosion rate for the specimen 7075 is larger than that of 6061 and 5083 aluminum alloys under the same conditions. So it means that the specimens 6061 and 5083 have high resistance to corrosion in NaCl solution After laser surface melting the results showed that the surface of aluminum alloys became more homogenous and pure after treatment.It was found that the corrosion current density decreases after Laser Surface melting at about three orders than that of untreated samples, therefore, the value of the corrosion rate of laser - treated alloy is smaller than that of the untreated. As well as the pitting corrosion potential after Laser Surface melting obviously shifted to more positive direction for all aluminum alloys in different concentrations of the NaCl solution.
