Lowly, low-tech iron is shaping up nicely for the 21st centu ry, thank you. SinterCast Inc. in Auburn Hills, Mich., has come up with an iron-casting process that can slash the weight of items such as engine blocks by up to 35% and cut the cost by 10%--yet still allow them to keep their strength.
The secret is compacted graphite iron, whose worm-like crystal structure makes it twice as strong as run-of-the-mill "gray" iron. Compacted graphite has been around for years, but foundries have been unable to produce it consistently. That's mostly because the raw material--scrap metal--contains impurities such as magnesium and titanium.
Now, Swedish metallurgist and SinterCast director Lennart Backerud has perfected a computerized system for measuring and regulating these impurities and other constituents of molten iron so it will unfailingly cool to form compacted graphite. Several U. S. auto makers are now evaluating the process. SinterCast hopes to charge foundries royalties of up to 20%, depending on a desired item's size and complexity.