CONSIDERED THE PREMIER ALLOY FOR ORBITAL ROCKET ENGINES
The requirement for high-performance, lightweight space propulsion systems has prompted rapid investigation of refractory metals that are capable of withstanding high stress levels at elevated temperatures, and also have a low ductile-to-brittle transition temperature for withstanding high frequency vibrations at cryogenic temperatures. Metals which demonstrate these requirements are the Niobium-based alloys. C-103 was selected to satisfy initial design requirements because of its excellent fabricability. C-103 is considered the most "forgivable" Niobium alloy from the standpoint of welding and forming. Hardware which has had as much as 600" (1524 cm) of TIG weldments formed after welding and coating has withstood a 2T bend at -195°C (-320°F) after the unit had completed its duty cycle.
Although it is considered a first generation alloy, succeeding Nb-1 Zr, C-103 was developed to replace the weaker alloys, but retain the desirable formability characteristics and welding properties. This Niobium-Hafnium-Titanium alloy satisfies most rocket engine applications for temperatures up to 1482°C (2700°F) because of superior mechanical properties at all temperatures. Extensive testing of coated components has shown that the reliability of Niobium has greatly reduced program costs as the components have been used for as many as ten times the duty cycle. Niobium also offers tremendous weight savings over many other rocket engine design materials. Metal Technology has over thirty-five years experience forming, forging, welding and machining the niobium Alloy C-103. It is one of our preferred materials to work with.
C-103 CHEMICAL COMPOSITION
Hafnium: 10.0%
Titanium: 0.7%-1.3%
Zirconium: 0.7%
Tantalum: 0.5%
Tungsten: 0.5%
MECHANICAL PROPERTIES OF C-103
Density: 0.320 lbs./in.3 or 8.85 gm./cm.3
Melting Point: 2350 ± 50ºC / 4260 ± 90ºF
Thermal Expansion: 8.73 ± 0.09 x 10 -6 (cm./cm.) ºC
Specific Heat: 0.082 BTU/ºF /lb