New materials and ALD design process provide robust sealing solutions for higher cylinder pressures and hotter exhaust temperatures in today’s heavy duty diesels
Federal-Mogul Powertrain, a division of Federal-Mogul Holdings Corporation (NASDAQ: FDML) is supporting the commercial vehicle industry’s drive towards greener, more efficient engines with sealing technologies that enable reliable operation at cylinder pressures up to 250 bar and exhaust temperatures up to 1000°C. The company’s hybrid Steel-Elastomer head gaskets combine proven multi-layer steel (MLS) technology and elastomeric fluid sealing in a single product that provides optimum sealing of both combustion gases and engine fluids. Its High Temperature Alloys (HTA) and High Temperature Coatings (HTC) seal exhaust joints reliably at temperatures beyond the capability of conventional stainless steel and graphite materials.
“Steel-Elastomer gasket technology builds on the success of MLS gaskets in providing optimised sealing loads around the combustion chamber, but goes much further,” explained Mike Gerulski, director, global research and development, Sealing, Federal-Mogul. “By adding elastomer sealing for the fluid passages, which require much lower loads to seal, we can concentrate the sealing forces where they are most useful. This opens up greater potential to design lighter, yet robust, engine structures and enables peak cylinder pressures up to 250 bar. Further, Federal-Mogul’s extensive expertise in material science enables us to develop elastomeric materials that address fluid compatibility and temperature interactions.”
Analysis-Led-Design to Optimize Sealing System Solutions
Steel-Elastomer gasket technology is applied using Federal-Mogul’s proprietary Analysis-Led-Design (ALD) process, which takes a holistic approach to optimise the cylinder head, block and gasket structure as a system. ALD drives the selection of the appropriate sealing technology and its verification. The process has become so well-established within Federal-Mogul that the company is able to reliably predict the sealing and durability behaviour of cylinder head gaskets before engine prototype hardware is readily available. “Through the use of ALD, we can help to eliminate costly engineering changes late in an engine’s development program,” said Gerulski.
Federal-Mogul also utilizes ALD for highly stressed gaskets in the exhaust system, where fluctuating high temperatures and system weight reduction driven by downsizing, turbocharging and exhaust gas recirculation (EGR) can result in flange distortion, making conventional static gaskets ineffective.
High Temperature Gaskets and Coatings Extend Thermal Range
Federal-Mogul’s HTA gasket materials address these challenges, providing reliable sealing performance at temperatures up to 1000°C, significantly higher than the current industry standard stainless steel. HTA gaskets are available with thermal performance characteristics matched to the individual requirements of a wide range of demanding applications, including turbochargers, downpipes, exhaust manifolds and EGR systems.
Equally important for reliable joint sealing was the development by Federal-Mogul of HTC coatings to ensure effective micro-sealing of the joint. An environmentally-friendly, water-based product, HTC provides a robust solution at elevated temperatures. “HTC demonstrates thermal stability to over 1000°C, while conventional coatings are reduced to ash at such temperatures,” said Gerulski.
Federal-Mogul’s advanced analysis techniques continue to provide greater insight into complex engineering problems and critical system interactions, according to Gerulski. “Our analytical capabilities are driving the ongoing development of key technologies that will help our commercial vehicle customers meet their increasingly challenging emissions and fuel economy goals, both now and in the future,” he said.
Federal-Mogul will present its advanced gasket and sealing technology at the IAA Commercial Vehicles Show in Hannover from September 23rd to October 2nd 2014, hall 13, stand C28.
