The Glass and Electronic Ceramics Department and the Ceramics and Glass Processing Department at the Sandia National Laboratories have developed a family of glasses to be used for hermetic sealing with high thermal expansion metal alloys. This sealing technology is expected to find widespread use in environments wherever weight saving is critical, for instance, in aerospace applications. This article has been prepared from information provided by R.K. Brow and L. Kovaic, Sandia personnel who have carried out this research. The hermetic aluminium sealing technology offers a lighter weight replacement for stainless stell components. In addition to weight savings, cost savings should be realised from the low temperatures required to seal the ALSG glasses (500 degrees C versus 900 degrees C for most silicate sealing glasses) and from the relative ease of machining aluminium as opposed to stainless steel. However, at this stage, the cost of phosphate glass preforms is expected to be slightly higher than economical silicate glass preforms. (from Authors)