| abstract |
A heat insulator for a hot isostatic pressing apparatus including a plurality of non-perforated graphite sheets; a plurality of perforated graphite sheets, each one of the plurality of perforated graphite sheets being sandwiched between and making at least substantially planar contact with, but not being bonded to, adjoining ones of the plurality of non-perforated graphite sheets; and a gas having an extremely low thermal conductivity substantially confined in the perforations in the plurality of perforated graphite sheets. |