aluminum foundry for you to sort out the corrosion types of aluminum in the process of processing?

One, a point of erosion. Also known as hole erosion, it is a localized erosion pattern that occurs on needle tips, dots and holes. Point erosion is a strange form of anodic reflection. It is a process of autocatalytic, that is, the precondition of the erosion process in the hole of the point is both promoting and maintaining the continuation of the erosion.

Two. Average erosion. Aluminum in the solution of phosphoric acid and sodium hydroxide, the oxide film on it will melt, the average erosion occurs, and the ablation speed is also average. The increase of solute concentration and the increase of solution temperature promote the corrosion of aluminum.

Three. Stress Erosion and cracking. A kind of breakage occurred in metal under stress (tensile stress or internal stress) and erosive medium is called SCC. SCC is characterized by the formation of eroded — mechanical cracks can grow along grain boundaries or through grain growth. Because the expansion of cracks is inside the metal, the strength of the metal structure will be greatly reduced, and it will be damaged suddenly. SCC is inevitable under the premise that they are:

Four, rift erosion. This is a kind of local erosion. Metal parts are in the electrolyte solution, because the metal and metal or metal and non-metal forming a crack, the width is enough to make the medium immerse and make the medium in a state of block. The phenomenon of the internal erosion of the cracks is called the rift erosion.