NCMS study reveals DI casting may mean cost savings.

In order to determine whether ductile iron (DI) could or should have a place in machine tool structure design decisions in the U.S., the National Center for Manufacturing Sciences (NCMS), Ann Arbor, MI, recently completed an assessment of basic material information and design philosophies with Dr Alex Zavaras of the Univ of Pittsburgh.

Among the findings of the study were:

* DI castings have been utilized successfully as a substitute for steel castings and/or fabricated steel in manufacturing small and medium size structural components for the last 20 years. In the last ten years, advances in computer and other technologies by foundries in Europe and Japan has made possible the production of highly reliable DI castings for large size, heavy section machine tool structural components;

* several U.S. foundries are producing multi-ton DI structural components, but not using fully the new technologies available has severely limited their ability to increase casting size and guarantee advanced properties;

* belief that the Europeans and the Japanese are far ahead of American industry in the use of DI technology was solidly confirmed due to their emphasis on research and development.

The competitive edge of technology in materials utilization will remain with the overseas competition unless unified action is taken, the study concluded. The U.S. needs to take a leadership role to: focus its efforts; organize networks to improve communications among foundries, machine tool manufacturers and R&D centers; spearhead the transfer of existing CAD/CAM technologies to the foundry industry; develop new technologies and solicit industry and governmental support for R&D; and support use in the nuclear industry.

According to Carl Swanson, director of Manufacturing Processes & Materials for NCMS, one of its member companies, Erie Press Systems, a subsidiary of EFCQ Inc, has played a champion role in the ductile iron project and has implemented several recommendations from the study, particularly in the manufacture of large hydraulic cylinders.

Gary Lunger, president of Erie Press and chairman of NCMS' Manufacturing Processes and Materials Technical Program Committee, explains that in uncovering current DI technology, several feasible applications of benefit to his company have been implemented. "We make huge presses and we have relatively clear specifications for what goes into each press," he says. "We have been able to use ductile iron as a substitute material primarily for cylinders and other parts at a significant cost savings over cast or fabricated steel."

Lunger says Erie Press has since looked at other applications for DI. "But because we deal in custom presses and don't have standard lines, we can't apply it across the board" he says. "However, we are looking at every press we produce for DI applications."

"The real value of the ductile iron study for all NCMS member companies," concluded Swanson, "is that the analysis showed that material cost savings ranging from 30-50% of equivalent fabricated structures could be realized in selected applications. The results of the study are now being evaluated for possible research activities and thrusts."

NCMS is a nonprofit organization, formed in 1986, that is bringing together, in partnership elements, the U.S. manufacturing community in an effort to lead manufacturing industries in the U.S. to a position of renewed global competiveness.