Corrosion of  metals involve  electrochemical reaction with electron transfer. With the oxide layer building, it could be barrier for the electron or ion or O tansfer which would reduce the electrochemical reaction thus acting as protective layer. The protectiveness depends on the nature of oxide layer and difiusion of ions or species through this oxide layer which would react with base metal. (The Diffusion could be inner or outer or sometimes both i.e. The base metal could diffuse out or reacting species like oxygn or hydrogen could diffuse in)

Usually a non conducting non porous layer and less impurity layer would act as excellent corrosion resistance layer like TiO2 or Al2O3.

Dear S. Prabhakaran could you rephrase your request. It is not clear enough what you are asking for. "ablative oxide layer" is oviously related to a welding process. What Kind of welding using which materials you refering to? 

Dear Rüdiger Rentsch, 

                                        It is a laser ablated metal surface which is having an oxide surface layer. I found this layer from the TEM analysis. Now you may be getting my point. For further please see the attached reference.

Corrosion of  metals involve  electrochemical reaction with electron transfer. With the oxide layer building, it could be barrier for the electron or ion or O tansfer which would reduce the electrochemical reaction thus acting as protective layer. The protectiveness depends on the nature of oxide layer and difiusion of ions or species through this oxide layer which would react with base metal. (The Diffusion could be inner or outer or sometimes both i.e. The base metal could diffuse out or reacting species like oxygn or hydrogen could diffuse in)

Usually a non conducting non porous layer and less impurity layer would act as excellent corrosion resistance layer like TiO2 or Al2O3.

Thank you Abhishek Sir.

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Laser ablation is a technology of surface material removing due to the laser beam incidence. The laser energy causes partial ionization and vaporization of the material. The goal of the process is to evaporate the material and simultaneously thermally affect  as few as possible the neighborhood of the treated area. This is achieved by introducing of the sufficient energy in a short time interval.( The concept is induced by the interaction of the focused laser beam incidence with the material surface).

 The corrosion resistance of the surfaces affected by laser ablation can be changed due to thermochemical processes. Independence on the various parameters which determines( the thermal load (J.mm-2) - line spacing, laser power, scanning speed and their combination with subsequent parameters as pulse frequency, pulse length, pulse shape, etc. we can obtain the different corrosion resistance of the metal surface).

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Thank you Ali Sabea Hammood

Dear S.Prabhakaran

The aftermath  of an oxide film formation on an ablated laser surface of a solid base metal would shield (protect) the base metal from the surrounding environment.   Consequently, the corrosion resistance of the base metal would improve. 

Thank you Habib.

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