subject: Aluminum Casting foundry electrochemical oxidation [print this page] Aluminum Casting electrochemical oxidation of aluminum surface lose electrons to become ions, and then the newborn with the anode to generate oxygen and oxide film formation. Oxidation in the film at the same time there are also chemical dissolution of oxide film. Oxide film formation rate with the anode current density, voltage increases and the solution concentration, temperature and speed, with the anodization time and slow down.
Of course, the chemical dissolution rate of oxide film with these factors also increase quickly. aging temperature and time selection depends on the performance requirements of the alloy, the alloy properties, the degree of supersaturation solid solution and casting methods. artificial aging can be divided into three categories: not entirely artificial aging, artificial aging and over full time. not completely artificial aging is the use of relatively low the aging temperature or shorter holding time, access to excellent mechanical properties, namely, to obtain a relatively high strength, good ductility and toughness, but the corrosion resistance may be lower. entirely artificial aging is the use of higher temperatures and longer aging long holding time, maximum hardness and the highest tensile strength, but elongation is low. over time are at higher temperatures, when the alloy to maintain a high intensity, while the plastic has increased, mainly in order to get good stress corrosion resistance. In order to get a stable organization and geometry, the limitation should be at a higher temperature. over time is often divided according to the requirement of stabilization treatment and softening.
