The material is called crystalline silicotitanate. Ill. The company specializes in molecular sieve ion exchangers and helped develop the granular form of the material. The sieve works in the form of a crystal lattice that has a net negative charge balanced by positively charged, mobile ions found in channels in the lattice. The mobile ions are exchangeable with other ions when placed in solution, and the spacing of the lattice s planes as well as its chemical environment are arranged to favor absorption of cesium, according to Jim E. Miller, one of the Sandia developers. Sealing Glasses for Hermetic Aluminum Electronic Components.
Steel is heavy, aluminum light.
The Achilles heel of previously developed phosphate sealing glasses had been that they dissolved in water over 1000 times faster than conventional silicate sealing glasses. But, by modifying the molecular structure of phosphate glass through the incorporation of aluminum oxide, we could improve its chemical durability to the point of being comparable to silicate glasses without sacrificing the desirable sealing properties, said Richard Brow, principal developer of the project. Another advantage of the new method, which has been patented, is that it makes reliable hermetic seals between aluminum alloy shells and copper alloy pins. We are unaware of any commercially available thermal expansion-matched glass that can directly seal copper contacts into an aluminum package, says Brow. Our method could improve the electrical performance of hermetic components.