Coatings niobium

The impressed current method with metal oxide-coated niobium anodes is usually employed for internal protection (see Section 7.2.3). In smaller tanks, galvanic anodes of zinc can also be used. Potential control should be provided to avoid unacceptably negative potentials. Pure zinc electrodes serve as monitoring and control electrodes in exposed areas which have to be anodically cleaned in the course of operation. Ag-AgCl electrodes are used to check these reference electrodes. 

Cathodic protection applications in fresh water include use of ferrite-coated niobium , and the more usual platinum-coated niobium . Platinised niobium anodes have been used in seawater, underground and in deep wells " and niobium connectors have been used for joining current leads Excellent service has been reported in open-seawater, where anodic potentials of up to 120V are not deleterious, but crevice corrosion can occur at 20 to 40V due to local surface damage, impurities such as copper and iron, and under deposits or in mud ... 

Buxbaum, R.E. and T.L. Marker, Hydrogen transport through non-porous membranes of palladium-coated niobium, tantalum and vanadium. /. Membr. Sci., 85, 29-38,1993. 

R.E. Buxbaum and T.L. Marker, Hydrogen Transport Through Non-porous Membranes of Palladium-coated Niobium, Tantalum, and Vanadium, 7. Membr. Sci. 85, 29 (1993). 

Fig. 1. Influence of pull and torsion on quenching curves in a transverse magnetic field of Nba-Sn-coated niobium wires dimensions diameter 0.5 mm, length 20 mm.

Nambu, T., Shimizu, K., Matsumoto, Y., Rong, R., Watanabe, N., Yukawa, H., et al. (2007). Enhanced hydrogen embrittlement of Pd-coated niobium metal membrane detected by in situ small punch test under hydrogen permeation. Journal of Alloys and Compounds, 446, 588-592. 

Buxbaum RE, Marker TL. Hydrogen transport through nanoporous membranes of palladium-coated niobium, tantalum, and vanadium. J Membr Sci 1993 85 29-38. 

The intended level of cathodic protection was achieved by locally fabricated potentlostats (see Figure 7) operating in conjunction with platinum coated niobium counter electrodes and a saturated calomel reference electrode. These consistently... 

Niobium carbide, coating Niobium carbide, coating FOF 0.19 0.13 3... 

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