logging in or signing up Corrosion dantescience Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 3849 Category: Education License: All Rights Reserved Like it (14) Dislike it (0) Added: October 31, 2009 This Presentation is Public Favorites: 7 Presentation Description No description available. Comments Posting comment... By: Siborasibora (38 month(s) ago) How can i get this plz help me i really need it for tomorrow :( plzzz Saving..... Post Reply Close Saving..... Edit Comment Close By: ayudhkumargupta (41 month(s) ago) get* Saving..... Post Reply Close Saving..... Edit Comment Close By: ayudhkumargupta (41 month(s) ago) can i het the ppt Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript CORROSION : CORROSION CORROSION : CORROSION Corrosion is a chemical change, in which a metal loses its properties because of a chemical reaction with its environment. Corrosion is a very slow process, can take decades depending on the metal involved. Corrosion looks different for different types of metals. IRON (Rusting) : IRON (Rusting) The corrosion of iron-based metals is called RUSTING Iron reacts with oxygen to form IRON OXIDE The oxygen can come from AIR or WATER IRON (Rusting) : IRON (Rusting) Rusting iron is POROUS What’s Porous? : What’s Porous? What’s Porous? : What’s Porous? IRON (RUSTING) : IRON (RUSTING) So What? Rusted metal will absorb water and “flake off” This exposes fresh un-rusted metal to water or oxygen This new metal will rust Costs billions of dollars Rust is Porous : Rust is Porous ALUMINUM : ALUMINUM Reacts with oxygen in the air to make ALUMINUM OXIDE The aluminum develops a layer of rust, preventing further corrosion. SILVER : SILVER SILVER : SILVER Silver does not rust, but tarnishes very slowly. Silver reacts with hydrogen sulfide found in food or water In this reaction, silver turns into silver sulfide. Silver Sulfide: Called “tarnish” A blue/black colour Slide 14: Spoon made of silver SILVER SPOON COVERED IN SILVER SULFIDE (TARNISH) SILVER : SILVER Let’s make silver tarnish quickly! Materials 1 piece of silver material 2 hard boiled eggs (only the yolk) 1 zip lock bag Procedure Boil eggs, remove egg yolks Place in ziplock bag, overnight in freezer SILVER : SILVER Preventing Corrosion : Preventing Corrosion Key – keep metal surface from having contact with oxygen Preventing Corrosion : Preventing Corrosion Materials to paint: Paint Oil Rust proof paint Prevention is based on stopping the metal from being exposed to OXYGEN in either air or water. You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.