iMAST Quarterly, Number 2, 2002
Abstract
Rhenium, as a pure refractory metal, is a very attractive material for high temperature structural and energy system applications such as solar-powered rocket engines, heat exchangers, and space and missile propulsion systems. Rhenium has many advantages over other candidate materials including tungsten. It offers excellent erosion resistance for components in high temperature rocket engines and hot gas valves. Rhenium has the second highest melting temperature next to tungsten. Unlike tungsten, it has a ductile-to-brittle transition temperature well below room temperature. Among the refractory metals, rhenium has the greatest tensile and creep-rupture strength at elevated temperatures. Rhenium cold work hardens and may only be worked 5-10 percent before requiring high temperature annealing to full recrystallization. Due to its unique high temperature physical and mechanical properties, the U.S. Navy has selected rhenium material for the solid divert attitude control system (SDACS) of the SM3 missiles program. Various components including thrusters, pilot valve tubes, gas supply tubes, strainers, rhenium coated graphite balls are needed to be manufactured for the SDACS unit. It is very difficult to manufacture net-shaped components made of refractory metals, i.e., rhenium. Typically, components are fabricated by either powder metallurgy (P/M) or chemical vapor deposition (CVD). Due to difficulties encountered in the P/M fabrication and shaping of refractory parts, CVD is mainly used in fabricating thin walled, small diameter or complex shaped components and also for coatings on carbon, ceramic and metal components. However, CVD process also has many shortcomings. Powder metallurgy techniques also have their limitations. Electron beam-physical vapor deposition (EB-PVD) method has been explored to meet challenges and goals of the SM3 program.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2002
- Accession Number
- ADA497098
Entities
Organizations
- Pennsylvania State University