Making Light Work of Ceramic Parts
To chefs and astronauts, the heat resistance of ceramics is what's important. Engineers like ceramics for their extreme durability. But whether these rock-hard materials are used for cookware, the skin of the Space Shuttle, or engine parts, they're usually molded into relatively simple shapes. That's because ceramics are too brittle to machine into complex shapes--unless an application can justify spending a few million on special diamond-tool grinding machines.
That is about to change. A Purdue University team led by mechanical engineering professor Yung C. Shin is developing a way to shape ceramic parts using ordinary machine tools plus a laser. The laser heats a pinpoint region to 1,800F, softening the ceramic's surface enough so that it can be removed easily. The trick is to remove the soft area immediately, before the heat can penetrate below the surface and damage the ceramic's properties. Shin expects laser-assisted machining to cut the cost of making ceramic parts by 50% or more--and allow the production of complex shapes that are now difficult or impossible to craft.
Diesel-engine parts could be reaping the benefits of the new method as soon as next year, Shin says. Further out, Shin believes that ceramics, with a boost from laser machining, could become a much more pervasive material. In fact, ceramics could be considered "wherever metal is now being used."By Adam Aston; Edited by Otis Port