Niobium RRR Superconducting

Niobium RRR standard

All niobium RRR superconducting products follow ASTM standard grade pure niobium R04220. ASTM B392 type 5 superconducting grade pure niobium.

Type 5(RRR Superconducting Grade Pure Niobium R04220)	Chemical Compositions Max Weight %
	C	N	O	H	Zr	Ta	Fe	Si	W	Ni	Ti	Nb
	0.003	0.003	0.004	0.0005	0.01	0.1	0.005	0.005	0.007	0.003	0.005	Balance

With the growth of radio frequency niobium superconducting cavity design, it is widely used in national and international world. The requests for niobium are also increased. Absolute pure metal only exists theoretically. Actually the metals we are applying more or less have impurities. Superconducting niobium usually contains O, C, N, H and Ta, Fe, W and etc. If the impurities are over limited range, the properties of superconducting niobium itself will be affected. Then its value will be influenced as high purity niobium superconducting material. Therefore, niobium RRR data is an important parameter to reflect purity and thermal conductance.

Niobium superconducting Residual Resistivity Ratio (RRR) is defined as the ratio of niobium superconducting resistivity and low temperature superconducting niobium resistivity under room temperature. With the increase of material’s purity and decrease of interior stress, RRR value is reduced. RRR value can be used to measure purity of the metal. Firmetal can produce Niobium products based on the RRR value customer required. RRR niobium is usually manufactured in shape of sheet, rod and tube. Regular dimension of sheet thickness is 2 to 5mm, while width is max 1000mm.

Niobium is an important rare metal. It has properties of high melting point with good processing, high temperature superconducting transition, excellent thermal conductivities and etc. These outstanding performances make niobium take an extremely essential effect on metallurgy, chemical engineering, aerospace, atomic energy, superconducting. Microwave superconducting cavity made of niobium has not only high accelerating field and small energy spread, but also long service life. Niobium is the best material to make superconducting accelerating resonant cavity.

Microwave superconducting cavity is applied in basic particle accelerator and straight-line superconducting accelerator. Niobium tubes are the main components in superconducting cavity. These superconducting accelerators greatly promote the improvements of physics, chemistry, materials science and geocosmogony.