MADI™ (MACHINABLE AUSTEMPERED DUCTILE IRON)

Major breakthrough in the production of high-strength, lightweight iron components for the automotive industry

Benefits:

• Selective ductile iron chemistries
• Unique, cost effective heat treatment cycles
• Novel microstructure
• High strength and fatigue-resistant variants
• Offers machinability similar to as-cast ductile irons
• Stronger than regular ductile iron at the same hardness
• Better fatigue properties compared to regular ADI
• Easier to machine than regular ADI
• Weight penalty compared to aluminum is <3% (estimated)
• Weight savings compared to forged steel is ~10% (estimated)


MADI™ is an innovative new ferrous-metal material developed by INTERMET for the casting of automotive structural and powertrain components such as suspension control arms and crankshafts. MADI™ has enabled INTERMET to manufacture ferrous-metal components for demanding, safety-critical automotive applications at lower cost, less weight, at higher productivity, and with much improved performance characteristics compared with any competing ductile-iron casting material.

A unique combination of metal chemistry and heat treatment has led to the invention of MADI™. Because the design strength of MADI™ is 50-100 percent higher than current as-cast ductile irons, significantly lighter weight components can now be designed. MADI™ will lead to the increased use of low-cost ductile-iron castings since for the first time improved mechanical properties and improved machinability both have been achieved.

MADI™ was originated by INTERMET’s Technical Services Group at the company’s Technical Center in 2001. It was developed to help the automotive industry meet increasingly stringent component weight and cost requirements.