Fe-Si Sintered Alloy for use in Exhaust Applications 2013-01-1154
As a result of the wide range of operating environments, component parts of automotive and commercial engine exhaust systems require a unique combination of material properties that are not easily met using existing wrought, cast, or powder metallurgy alloys. Alpha Sintered Metals (ASM) now offers a new Powder Metal (PM) alloy with improved hot oxidation properties that not only supplements the application of traditional stainless steel alloys but also enhances the service life reliability of these components for elevated exhaust temperature applications.
ASM's new alloy named Alphaloy, demonstrates material property advantages for several critical exhaust system attributes. The test results of studies comparing Alphaloy to other traditional materials exhibit improved performance relative to hot oxidation resistance, tensile strength and machinability while maintaining consistent performance for thermal expansion, atmospheric corrosion and weldability. Alphaloy's excellent resistance to degradation from thermal cycling offers dramatic performance improvement over 400 series stainless steel materials.
The paper also reviews and discusses some current exhaust industry practices that promote improved sealing and longer useful life requirements. Furthermore, progressive emission reduction initiatives will increase demand for PM flanges in fabricated manifolds, complex diesel after treatment systems such as Diesel Oxidation Catalyst (DOC) and Selective Catalytic Reduction (SCR) and new cooled Exhaust Gas Recirculation (EGR) systems. Alphaloy's unique combination of physical and mechanical properties is ideal for many of these applications.