AERODYNAMIC TRAPPING AND LASER-HEATING FOR CONTAINERLESS GLASS PROCESSING IN MICROGRAVITY

In analyzing the characteristics of the aerodynamic trap-laser heating apparatus, it is shown that it possesses most of the qualities needed for containerless glass (or other material) processing, on the ground and in reduced gravity. Some of the effects of laser heating and melt ing, and of aerodynamic trapping are studied with respect to their inf luence on vitrification and glass quality, especially in reduced gravi ty. The experiments were carried out on very high melting paint (over 1500 K) silica and alumina bearing compounds, and in particular calciu m aluminate. With the flight hardware, it was possible to vitrify, on the ground, 3.6-mm-diam spherical samples of 50CaO-50Al(2)O(3) (CA) (% mol), with a 100-W, 3-mm spot, CO2 laser beam, and a 0.5-l/min gas fl ow. Alumina samples were successfully melted during aircraft parabolic flights. A discussion of trapping ability with respect to sample temp erature (and viscosity) is presented.