Vacuum Impregnation for aluminum die casting products
Vacuum impregnation is an effective means to heal the inner pores of aluminum high pressure die casitng products. The porosity of high pressure die casting part is a big and troublesome disadvantage compared with other aluminum castings. Especially for die cast automotive cylinders, the inner pores can lead to terriable linkage and even blasting. Commonly, the pressure load required die casting products should be processed by impregnation, and checked by x-ray inspeciton finally.
Parison has set up an impregnation line for our own die cast aluminum automotive parts. We are aiming to be an automotive die cast part leading manufacturer. Auto part involving equipments have been introuded to achieve our aim.
Impregnation process for die casting
- Before impregnation, porosity within the aluminum castings must be completely clean and dry.
- Impregnation: The aluminum casting parts are suspended in a basket before being lowered and immersed in sealant in a pressure autoclave. The vacuum is then released, forcing the sealant deep into the porosity.
- Drain: The drain cycle involves removing excess sealant from aluminum castings after impregnation. Effective draining is essential to reduce any "carry over"to the cold wash tank and limit the amount of sealant lost as effluent. The removed sealant is then collected and automatically returned to the autoclave.
- Cold Wash: After draining, aluminum castings are transferred to the cold wash tank to remove surface sealant.
- Hot Cure: This takes place in a separate tank with water controlled at a minimum of 90ºC (195ºF). so as to cure the sealant within the porosity and to provide a very effective final washing action for the aluminum casting parts.
Porosity types in aluminum die casting parts
Flow porosity, resulting in surface or internal defects caused by poor pressure conditions in the process.
Gas porosity, usually internal, caused by trapped gases of various kinds in the die. Shrink porosity, the most common and most difficult to control, caused by the change in volume as the metal changes state from liquid to solid.
Vacuum impregnation is the permanent solution to the porosity problem of aluminum casting parts, filling any void with a stable yet flexible material that is resistant to attack from heat, oils or chemicals. The process is sub-surface and can be performed on raw materials or the finished machine part, causing no dimensional change or contamination to the aluminum casting parts.
Come to other post treatment for die casting
- rapid prototype,die casting and mold design
- CNC machining, precision machining, finishing
- polishing,mirror polishing,brushing
- electroplating: nickel, chrome plating
- powder coating
- e-coating,electrodeposite,electrophoresis
- painting,lacquering,stoving varnish
- chromate passivation, phosphating
- impregnation
- laser cutting, silk screen
- sand blasting, ultrasonic cleaning, tumbling
- assembly and retail packaging
Aluminum die casting impregnation equipment
