Robust, High Temperature Containment Cartridges for Microgravity

High temperature, corrosion resistant cartridge materials are needed for microgravity processing experiments. Tungsten and molybdenum have high melting temperatures and in general possess the required chemical inertness. To improve the mechanical properties of these materials, alloy additions such as rhenium are necessary. Recently, thin-walled, closed-end cartridges have been fabricated from elemental blends of molybdenum-rhenium powders. However high temperature heat treatments are necessary to alloy elemental blended powders. Problems with distortion, intermetallic formation and incomplete alloying have occurred. To overcome these problems, an innovative Plasma Alloying and Spheroidization (PAS) process is being developed to produce pre-alloyed molybdenum-rhenium and tungsten-rhenium powders. Benefits of the PAS process such as a two-order magnitude reduction in oxygen contamination, enhanced flow characteristics, ability to produce pre-alloyed refractory metal powders and the ability to reduce heat treatment processing time were demonstrated during Phase I. During Phase II, the PAS process will be optimized. The optimized PAS Mo-Re and W-Re powders will be used for the production of robust, high temperature QMI and GEDS cartridges for microgravity processing experiments.