Laser machining of glass-ceramic materials

A method for fabricating a glass-ceramic radome, comprising the steps of:

• providing a radome blank made of a glass-ceramic material and having a longitudinal axis, and further having an inside surface and an outside surface;
• providing a high-power Nd:YAG laser with a set of operating parameters comprising operating in a pulsed wave mode with a square wave pulse having a pulse duration of from about 0.3 to about 3 milliseconds, a pulse frequency of from about 50 to about 500 pulses per second, and a pulse intensity of at least about 3.times.10.sup.4 Watts per square centimeter;
• rotating the radome blank about the longitudinal axis at a rate of rotation corresponding to a feed rate of from about 100 to about 800 inches per minute;
• rough machining a rough-cut layer of the glass-ceramic material from a rough-machining surface of the radome using the high-power, Nd:YAG laser simultaneously with the step of rotating arid with a point of application of a laser beam from the high-power laser traversing along the radome blank generally parallel to the longitudinal axis of the radome blank, the rough machining surface being selected from the group consisting of the inside surface and the outside surface of the radome blank,
• wherein the feed rate and the set of operating parameters of the high-power Nd:YAG laser produce a material removal rate of at least about 1 cubic centimeter per minute during the step of rough machining;
• and
• final machining glass-ceramic material from the rough-machining surface by mechanically grinding a final-machining layer at least about 0.002 inches thick of glass-ceramic material from the rough-machining surface.

A method for fabricating an article of a glass-ceramic material, comprising the steps of:

• providing a blank made of a glass-ceramic material;
• providing a high-power Nd:YAG laser operating with a set of operating parameters comprising a pulsed wave mode with a square wave pulse having a pulse duration of from about 0.3 to about 3 milliseconds, a pulse frequency of from about 50 to about 500 pulses per second, and a laser pulse intensity of at least about 3.times.10.sup.4 Watts per square centimeter;
• and
• machining a layer of the glass-ceramic material from a surface of the blank using the high-power laser and with a point of application of a laser beam from the high-power Nd:YAG laser traversing relative to a surface of the blank at a feed rate,
• wherein the feed rate and the set of operating parameters of the high-power laser produce a material removal rate during the step of machining.