Ions on the Prize

What do coin mints, sheep farmers and carmakers have in common? All depend on metal tools that wear out sooner than they would like. Although sheep farmers can just pick up a new pair of shears, the down time required to switch tools in a factory can be among the most costly components of manufacturing.

That’s why a 17-member consortium led by the General Motors Research and Development Center is pushing a new materials-hardening technology-plasma-source ion implantation. The automotive industry alone hopes to realize billions of dollars’ worth of savings every year, mainly from increasing the time between tool changes, says Michael Dudzik, a physicist at the Environmental Research Institute of Michigan and the general manager of the consortium. According to Dudzik, ion implantation can boost tool life from two- to tenfold.

The notion of treating surfaces with ions isn’t new. But conventional methods shoot a beam of ions at the target. That method works well for flat surfaces but not for irregular parts. In the plasma approach, by contrast, the piece is placed in a vacuum chamber and zapped with thousands of volts of negative charge. Then the chamber fills with a cloud of nitrogen ions (the plasma), which bombard the charged metal surface with high energy; the ions infiltrate the outer skin of the metal, reaching nooks and crannies inaccessible to conventional ion beams, and radically augment surface hardness.

Four years after its formation, the consortium is starting to apply the technology to industrial-scale mass production.

“The real need is to do this in high volumes,” explains Dudzik. “That means it has to work in an assembly line setting without PhDs monitoring it. The process has to be bulletproof.”