Researchers at Purdue University have developed an innovative technique for machining brittle ceramic materials that will make the low‑volume production of intricate components much less costly. The technology, developed by Yung C Shin, a professor of mechanical engineering, uses the heat from a laser to soften a tiny area of the component just before it is machined, thus reducing wear on the tooling.
The laser heats the material to more than 1000°C while it is being machined, making it softer and more ductile. Positioning of the laser is carefully controlled so that only the small area that is next to be machined is heated. The softened ceramic is then removed using a cutting tool made from cubic boron nitride. A very small, shallow layer of the surface is heated, and then removed immediately so that the interior is not damaged by heat.
The technique is past the experimental stage, and could be commercially available within a year. The research team is hoping to reduce manufacturing costs by at least 50%. Laser‑assisted machining could prove much more cost‑effective for low‑volume ceramic components than the conventional method of grinding using diamond tooling. This can amount to as much as 75% of the total cost of making a part. Shin says that a major advantage of the technique is that complex geometry can be created in a single process, whereas multiple stages, and therefore multiple machines, can be required for diamond grinding. Equipment savings could be considerable. However, the technology will not replace the bulk manufacturing of ceramic components using die forming. The costs of designing and creating a die make this viable only for large numbers of components.