Method for preparing Ni-Ti surface tantalum coating with electrodeposition in room temperature molten salts

Abstract

The invention belongs to the preparation of functional material coatings, in particular to a method for preparing a Ni-Ti surface tantalum coating with electrodeposition in room temperature molten salts. The method comprises the following steps: adding any one of bis-trifluroro sulfonic acid imine butyl pyrrole (CF3SO2) 2N-BPy or chlorinated butyl pyrrole BPy-Cl into any one of lithium halide or bis-trifluroro sulfonic acid imine lithium (CF3SO2) 2N-Li, then adding K2TaF7 or TaCl5, providing tantalum sources, and forming electrolyte; an anode material is graphite or metal tantalum, and a cathode material is Ni-Ti alloy; carrying out electrodeposition at the temperature of 10-40 DEG C higher than the liquidus temperature of the electrolyte, wherein the electric current density is 0.005-0.01A / cm<2>; electrolyzing for 3-5 hours to obtain the compact tantalum coating on the cathode surface. The electrodeposition temperature is low, the operation is convenient, and the cost is low. The tantalum coating with uniform components can be obtained by controlling the electric current density.

Description

technical field [0001] The invention belongs to the preparation of a functional material coating, in particular to a method for preparing a Ni-Ti surface tantalum coating by electrodeposition of molten salt at room temperature. Background technique [0002] Nickel-titanium shape memory alloys can be used to make medical devices and surgical implants, such as cardiovascular stents. It is a functional material with good biocompatibility and corrosion resistance and is widely used in the field of medical biomaterials. But nickel and its compounds are potentially toxic to the human body. The side effects of using Ni-Ti alloys as skeleton joints in patients. Because after the Ni-Ti biometal material is implanted into the body, Ni dissolves in body fluids in body fluids containing various salts. First, it causes corrosion damage to the Ni-Ti alloy, and second, Ni forms metal hydroxides or chlorides in the body ( These substances have a great impact on the body's immune system, ...

AI Technical Summary

Problems solved by technology

So far, various methods such as physical chemistry, electrochemistry, morphology and biochemistry have been used to modify the surface of nickel-titanium memory alloys, such as: surface tantalum plating, surface ceramic coating, surface bioactive coating, etc. The purpose is to form a passivation protective film on the surface of the Ni-Ti alloy, but there are certain disadvantages: (1) The method of surface tantalum plating is to plate tantalum on the Ni-Ti alloy plate, which can improve X-ray visibility and further improve The anti-corrosion performance inhibits the dissolution of Ni ions and improves biocompatibility; but the disadvantage is that it is impossible or difficult to prepare coatings on the surface of workpieces and devices with large aspect ratios and complex shapes; (2) The surface ceramic coating method is through various A method to prepare a ceramic layer on the surface of Ni-Ti, such as the sol-gel method to prepare phosphorus-containing TiO 2 thin film or Ca / P layer (Ca 5 (PO 4 ) 3 (OH) and a small amount of α-Ca 2 P 2 o 7 and Ca 3 (PO 4 ) 2 Composition, can improve its biocompatibility), surface oxidation method to prepare TiO 2 film, surface nitriding to prepare TiN, etc.; but the disadvantage is that TiO 2 The corrosion resistance of the film is not as good as that of the tantalum film, and the tantalum film is not subject to any corrosion in contact with body fluids; (3) The surface bioactive coating method is to use surface vacuum vapor deposition of C-type parylene, and make it into a reticular blood vessel Stent, implanted in animal blood vessels for animal experiments and biocompatibility studies; but the disadvantage is that the vacuum vapor deposition method has low efficiency and high cost

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