Excimer laser processing of ceramic-based Functionally Graded Materials

The production method of Functionally Graded Materials (FGMs) and characteristics of FGMs in laser processing is described. FGMs were produced by a progressive lamination method. This method is useful in producing thick blocks of FGMs. From images of FGM sections taken with a scanning electron microscope (SEM), it was observed that grains of the two component materials existed together and that the distribution of the respective grain types were graded continuously throughout the sample thickness. For the laser processing, an XeCl excimer laser with a wavelength of 308nm, a maximum pulse energy of 500mJ and a pulse duration of 30ns was used. Characteristics of the FGMs in laser processing were estimated. Saturation characteristics of the hole-depth were observed for a specific range of laser pulse numbers. It was found that characteristics of the laser processing velocity depended on the ceramic-metal content of the FGMs.