Diesel and gasoline turbo gaskets benefit from new manufacturing process that overcomes sealing uniformity issues resulting from welding different materials.
Federal-Mogul Powertrain, a division of Federal-Mogul Holdings Corporation (NASDAQ: FDML), has overcome an increasingly common sealing challenge on turbocharger outlet flanges where the gasket comprises multiple layers. The company has developed a new manufacturing process that eliminates the sealing issues that can occur when welding dissimilar materials.
"There is a known product quality challenge arising from the use of turbocharger gaskets made from a number of layers," explained Thorsten Schäfer, Global Engineering Manager Rigid Heat Shields, Federal-Mogul Powertrain. "When stainless steel and aluminum-coated steel are welded together a reaction can occur that compromises sealing integrity in the finished part. A recent design optimization opened the door for this new welding manufacturing process thereby eliminating the issue."
The gasket for a turbocharger outlet flange comprises a thick steel distance layer that is aluminum-coated for corrosion resistance and to reflect heat, sealed on both sides by functional stainless steel layers, each with a sealing bead. To avoid handling multiple separate parts, all three layers are welded together but this can create known issues with sealing uniformity because the aluminum coating can react during welding, creating bubbles that generate high spots on the sealing face, leading to variations in contact pressure.
Federal-Mogul Powertrain's solution is to have three holes blanked out of the distance layer and three dimples created in both of the sealing layers. This ensures accurate location of the separate components, allowing the functional outer layers to be spot-welded to each other directly through the dimples without affecting the material in the distance layer, uniting the whole assembly.
The new process has been in high volume production at the company's sealing production site Herdorf, Germany for several months and has proven successful. Federal-Mogul Powertrain believes it will also be equally effective for many other applications where functional gasket layers are combined with a coated distance layer or heat shield, on both gasoline and diesel engines.
"Developments such as this new manifold gasket technology demonstrate Federal-Mogul Powertrain's commitment to providing robust solutions to issues as they arise," said Gian Maria Olivetti, Chief Technology Officer, Federal-Mogul Powertrain. "As challenges like increasing temperatures of turbocharger installations are identified, we have the experience and expertise to move quickly to meet the needs of our customers, whatever the issue."