PROCESS FOR PRODUCING A QUARTZ GLASS CRUCIBLE HAVING A TRANSPARENT INNER LAYER OF SYNTHETICALLY PRODUCED QUARTZ GLASS

摘要

The invention is based on the object of specifying a cost-effective process for producing a quartz glass crucible having an inner layer of transparent, synthetically produced quartz glass which is distinguished by a long service life. According to the invention, this object is achieved by a process comprising the following process steps: (a) a gas-permeable crucible substrate having an inner side is produced by solidifying at least the surface of a layer of SiO₂ particles, (b) a porous SiO₂ soot layer is deposited on at least a partial area of the inner side of the crucible substrate by vapour deposition, and (c) the porous SiO₂ soot layer and at least part of the crucible substrate are subjected to vacuum-assisted sintering by means of an arc and under a vacuum which acts over the wall of a vacuum fusion mould, to form the quartz glass crucible and the inner layer of transparent quartz glass.