Die-cast metals of high durability are an integral component of automobiles. Automobiles need protection from external threats such as moisture and other corrosive fluidic agents in the interior and exterior. The use of lightweight electronic parts and raw materials that can maintain a uniform build and regulate safety systems will require eliminating potential loopholes.
However, you should note that it’s difficult to totally avoid loopholes such as minuscule holes, leakage paths, and porosity in casted electronic automobile components like coils. These loopholes can spread all over electronic components of cars, resulting in several failures. Fluids, minuscule particles, and moisture may leak into casted areas and find their way into the leakage path, thereby negatively impacting the electronic systems.
Sealing is an essential process in the production of die casts for automobiles. It helps protect against fluid leakage apart from increasing the lifespan of automobile components. The use of light materials in die casting will produce parts with thin walls but a complex design. However, these components can be susceptible to porosity, and a process like vacuum impregnation can provide a solution.
Porosity in Die Cast Automotive Components
Die-Cast Automotive Parts like hybrid and battery electric power trains, transmissions, cylinder heads, engine blocks, and compressors must pass fundamental quality testing. There can be a compromise in the performance of systems and components if porosity becomes undetected in any single cast part.
Compressors are the most susceptible automotive component to porosity. They must be capable of operating at an internal temperature not less than 150°C and are required to be pressure-tight as high as 18 bar. The compressor will not function appropriately if there’s the slightest contamination or leak. The only option left to manufacturers if they detect a leak in compressors at the final assembly stage is to disassemble and scrap about 90% of the non-cast parts, which is a very costly process.
Generally, porosity is almost impossible to avoid in die-cast production. That is due to the effect of variables such as die release agents, trapped gases, pressure, flow, and molten material volume, all of which contribute to porosity at various points in the die-cast production process.
Vacuum Impregnation
Vacuum impregnation is used for sealing components and safeguarding automobile components from external threats. The casted components are often carbon fiber reinforced plastic, steel, magnesium, and lightweight aluminum. The changes in the design of these components further reduced their weight. The lightweight contributes to thinner walls and adds complexity to the design, making them prone to porosity during the casting process. There are three vacuum impregnation methods: dry, wet, and pressure vacuum impregnation.
Vacuum impregnation generally works by submerging the automotive component in water and forcing it through an air pressure of 5psi to help detect porous voids. As forced air rushes over the openings, the leakage becomes more vivid to the eye. This process is a proven solution for sealing the porous gaps in die-cast components of electronic and automotive parts. It helps to rid the components of scrap caused by porosity, reduces the labor cost, saves many resources, and cancels the warranty needs of the car owner as a result of a top-quality finish.