Abstract: A crucible for preparing a single crystal which comprises an iridium-rhenium alloy comprised of from about 80 to about 99 parts of iridium and from about 1 to about 20 parts of rhenium. The crucible has excellent creep resistance and compatability properties and is especially useful for the preparation of gadolinium-gallium-garnet crystal.

Abstract: This invention relates to an arc erosion-resistant composite material and methods for its manufacture and, more specifically, composite arc erosion resistant materials useful as electrodes in spark plug and jet engine igniters to promote longer useful life. An arc resistant material in particulate form is dispersed throughout a lower melting matrix metal clad in a tube of nickel or nickel alloy, and then worked to a very small outside diameter, after which the composite may be cut to provide electrode elements. Ruthenium and iridium, and their alloys comprise the arc erosion resistant material. Suitable matrix metals comprise silver, gold, copper, nickel, and palladium.