Writing conducting lines into alumina ceramics by a laser dispersing process

The objective of this work is the development of a laser-supported process that allows to modify the electric and thermal properties of ceramics on a local scale. The principle of the process is based on local melting of the ceramic by a CO2 laser beam and application of an additive to the molten area on the surface. During solidification, a metal–ceramic composite is formed with modified material properties compared to the bulk material. Different alumina samples were treated with metal powders of tungsten, copper, and oxides of these metals. Scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX) analysis reveal that the physical and chemical properties of a peripheral zone are changed in the heated region down to a depth of approximately 500 μm. The resulting resistance of the laser tracks can be adjusted from semi-conducting to metallic behavior with a resistivity down to 2×10−6 Ω/m. The modified ceramic can be used for heating elements working at operation temperatures of up to 1000 °C, high current resistance which can be loaded with current of up to 100 A.