Nb-1 Zr Alloy
It was discovered that the addition of 1% zirconium to niobium greatly improved the creep strength over the soft pure metal. Thus Nb-1Zr became the replacement for pure niobium in applications requiring the chemical resistance of niobium and a material with high melting temperature. In addition to greatly increasing the strength of pure niobium at higher temperatures, Nb-1Zr also has low thermal nuclear capture cross-section properties. Therefore, this alloy has been closely associated with the nuclear industry, which requires specified elevated temperature strength in the range of 1800º F to 2200º F. Because of the increasing need for better strengths, as technology has advanced, Nb-1Zr has been replaced by alloys such as C-103, which has greater strength and thus improved reliability, but still retains all the desirable characteristics of Nb-1Zr. Nb-1Zr has the advantage of being less expensive than the higher strength alloys, and can be used in applications where a high temperature material is needed with low loads such as a load free thermal shield. Due to the excellent fabricability and ductility, this material is readily available in all desired mill product forms.
PHYSICAL PROPERTIES of Nb-1Zr
Density 0.31 lbs./cu. in. or 8.57 gms./cu. cm.
Melting Point 4365 ± 15ºF or 2410 ± 10ºC
Thermal Conductivity 24.2 BTu/(hr.) (ft.)2 (ºF/ft.) (25ºC)
Nb-1Zr Chemical Composition
| Tungsten | 500 ppm |
| Halnium | 200 ppm |
| Tantalum | 1000 ppm |
| Zirconium | 0.8% 1.2% |
| Carbon | 200 ppm |
| Oxygen | 300 ppm |
| Nitrogen | 100 ppm |
| Hydrogen | 15 ppm |
Portions of the information are copyrighted by ATI Wah Chang and are reproduced here by Metal Technology with the permission of ATI Wah Chang, Albany, Oregon 97321.
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