Casting Study: Air Extractor Cover

Major Selection Criteria: Good Finish, Net Shape
Alloy:
Application Field: Automotive
Application Size: Large
Surface Finish:
Casting Technique:
Source: France

airextr3_photo3_caseID60In their original version, these parts were produced in glass fiber reinforced resin, 3-4.5 mm thick and containing two brass inserts to fix them to the car body. These components are painted on the body to match the rest of the car. Problems encountered during stoving the paint include distortion and blistering, which led to a high amount of retouching work. This led the carmaker to zinc die castings. The zinc die cast parts – 1.2 mm thick – are much more rigid, which makes for better assembly with the steel sheet bodywork. Additionally, they do not distort during stoving. Thanks to new die casting technology, the parts are cast with excellent surface quality and are free from porosity, so they can be stoved at high temperatures without blistering. They are delivered with a chromated surface so that they can go directly to painting with no other preparation. The use of thin wall sections and elimination of the brass inserts make the zinc die castings a cost-effective option compared to the previous material.