Tantalum Cladding and Coating Techniques

Loose lining. The loose-lined construction is used to make thick tantalum liners and was historically the first approach to a duplex system. The tantalum liner is manufactured separately and inserted into reactor vessels without bonding with the structural base metal. This loose-lined construction is the most economical and most widely used fabrication method throughout the entire industry. Liner thicknesses of 0.5 to 1 mm are satisfactory against corrosion. It is also possible to improve this technique by welding the liners to the base metal (i.e., weld overlay). Although economical, the loose-lined construction has some intrinsic drawbacks  

Danzig, I.F. Dempsey, R.M. La Conti, A.B. (1971) Characteristic of tantalided and hafhided samples in highly corrosive electrolyte solutions. Corrosion 27,55-62. 

Whiting, K.A. (1964) Cladding copper articles with niobium or tantalum and platinum outside. US Patent 3,156,976. 

Cardarelli, F. Taxil, P. Savall, A. (1996) Tantalum protective thin coating techniques for the chemical process industry molten salts electrocoating as a new alternative. Int. J. Refract. Metals Hard Mater.,14, 365-881. 

Explosive bonding and cladding. In this method, the controlled energy of a detonating explosive is used to create a metallurgical bond between tantalum and the base metal. A copper intermediate layer is used when tantalum is clad onto carbon steel in order to avoid brittle intermetallic formation at the interface. The limitations of the explosive bonding are as follows  

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