The effect of pigment addition in diode laser ablation machining of ceramic/polymer composite material

This paper reports on the laser machining of ceramic materials by the ablation of a low temperature pigmented polymer binding material. Through initial compacting and in®ltration of various blends of ceramic powder with a low temperature polymer binding material (with added pigments) it is possible to ablate the composite material with much reduced energy requirement compared to that for solid ceramic blocks. It was found that out of three different black pigments tested (graphite plasticiser, ink and powder paint) the powder paint proved to be the best form of pigmentation to be added to the composite mixture in order to achieve increased laser beam absorptivity and machinability. The variation of laser beam absorptivity with the amount of pigment was established. It was found that the laser beam absorption could be increased from 12% without any pigment to over 90% with just over 1% pigment. # 2000 Elsevier Science B.V. All rights reserved