Lightweight Castings

May 1, 2014

Ryan Gehm

Grede is developing lightweight chassis, powertrain, and drivetrain components—including safety-critical systems—for several heavy-equipment manufacturers using a patented ductile iron alloy called SiboDur. SiboDur is an ultra-high-strength ductile iron with a unique chemistry and process. Parts made from the alloy compete favorably with aluminum in terms of weight reduction, according to Grede, and offer high structural performance and durability, as well as integration for part complexity reduction. Five different SiboDur alloys are available, each offering select chemistries that can improve fatigue strength and functional design optimizations to match the requirements of specific applications. For example, SiboDur’s Ultimate Tensile Strength ranges from 450 to 800 MPa, with elongation percentage ratios of 6 to 23%. Grede also utilizes sophisticated topography and finite element analysis to create precise casting geometry to match the individual load case and stress strain vectors where it is needed. Heavy-equipment manufacturers worldwide are using, developing, and testing SiboDur in a variety of components for current and future vehicle programs. These include safety-critical parts with high stress and torque requirements, such as steering knuckles, axles, control arms, hubs, brake rotors, engine mounts, crankshafts, and suspension links. SiboDur was developed by Swiss-based Georg Fischer Automotive AG. Grede has an exclusive license to produce the alloy in North America.