Cold-sprayed tantalum coatings and related methods
Plasma devices are provided, which in embodiments, comprise a surface and a cold-sprayed tantalum coating adhered to the surface, the coating configured to absorb a hydrogen species from an atmosphere comprising a plasma generated in the plasma device. Methods of making the coatings and using the plasma devices are also provided.
1 . A method comprising:
generating a plasma within an inner volume of a container of a plasma device such that the plasma is surrounded by a gaseous region including a hydrogen species, wherein a coating including cold-sprayed tantalum is disposed on a surface of the inner volume;
heating the plasma to a first temperature of at least about 500 K such that the coating absorbs at least a portion of the hydrogen species;
cooling the plasma to a second temperature less than the first temperature such that the coating retains the absorbed portion of the hydrogen species; and
heating the coating to a third temperature, the third temperature greater than the second temperature and less than or equal to about 1000 K such that the coating desorbs at least a portion of the hydrogen species to at least partially regenerate.
2 . The method of claim 1 , wherein the coating absorbs at least about 10 19 hydrogen species/cm 2 after heating to the first temperature and before cooling to the second temperature.
3 . The method of claim 1 , wherein the hydrogen species includes at least one of a deuterium species or a tritium species.
4 . The method of claim 1 , wherein the gaseous region has a pressure of 10 −1 mbar or less.
5 . The method of claim 1 , wherein the hydrogen species comprises hydrogen in its atomic form, hydrogen in its molecular form, an isotope of hydrogen in its atomic form, an isotope of hydrogen in its molecular form, or combinations thereof.
6 . The method of claim 1 , wherein the coating is in direct contact with the plasma.
7 . The method of claim 1 , wherein the plasma is characterized by at least one of a temperature of at least 500 K, a pressure of 10 −1 mbar or less, an ion flux of at least 10 15 D/m 2 s, an ion energy of at least 1 eV, and an incident fluence of at least 10 20 D/m 2 .
8 . The method of claim 1 , wherein the surface is stainless steel.
9 . The method of claim 8 , wherein the surface is one of a stainless steel panel or a plurality of stainless steel panels mounted within the inner volume of the container.
10 . The method of claim 9 , comprising the plurality of stainless steel panels, wherein some stainless steel panels of the plurality are mounted proximate to walls of the container so as to provide direct contact with the gaseous region surrounding the plasma, but not direct contact with the plasma, and at least one stainless steel panel of the plurality is mounted away from the walls of the container and spaced apart from the stainless steel panels that are proximate to the walls of the container, to provide direct contact with the plasma.
11 . The method of claim 1 , wherein the coating consists of tantalum.
12 . The method of claim 1 , wherein the coating is mechanically and metallurgically bound to the surface.
13 . The method of claim 1 , wherein the coating has an average thickness of at least 150 μm.
14 . The method of claim 1 , wherein the coating has a hardness of at least 150 HV 0.050 .
15 . The method of claim 1 , wherein the coating defines a plurality of micro-voids distributed throughout the coating.
16 . The method of claim 15 , wherein the plurality of micro-voids comprises micro-voids having a largest dimension of at least 3 μm.
17 . The method of claim 15 , wherein the coating has a porosity of less than 2%.
18 . The method of claim 1 , wherein the coating defines a fine grain structure with a large area of grain boundaries and other micro-voids.