Self-healing metal composite tube walls

A method of forming a tubular structure arrangable in a foreign fluid having an ambient pressure, the structure comprising an outer tube, an inner tube arranged within the outer tube, and at least one chamber formed between the outer tube and the inner tube, the method comprising:

• forming the at least one chamber;
• and
• arranging at least one self-healing material in the at least one chamber, wherein the self-healing material is configured to solidify and/or expand upon contact with the foreign fluid and wherein the at least one chamber has a chamber pressure that is lower than the ambient pressure,
• wherein the foreign fluid is one of ambient air and water, and
• wherein when a hole is formed in a wall of the outer tube, due to the chamber pressure being lower than the ambient pressure, the foreign fluid enters the at least one chamber through the hole formed in the wall of the outer tube and contacts and reacts with the at least one self-healing material to solidify and/or expand the at least one self-healing material to form a solidified section within the at least one chamber that seals the hole.

A method of sealing a hole in a tubular structure arranged in a foreign fluid having an ambient pressure, the tubular structure comprising an outer tube, an inner tube arranged within the outer tube, at least one chamber formed between the outer tube and the inner tube, wherein the at least one chamber is maintained at a chamber pressure that is lower than the ambient pressure, and at least one self-healing material arranged in the at least one chamber, wherein the self-healing material is configured to solidify and/or expand upon contact with the foreign fluid, the method comprising:

• contacting the self-healing material with the foreign fluid such that the self-healing material solidifies and/or expands to form a solidified section;
• and
• sealing the hole with the solidified section,
• wherein when a hole is formed in a wall of the outer tube, due to the chamber pressure being lower than the ambient pressure, the foreign fluid enters the at least one chamber through the hole formed in the wall of the outer tube and contacts and reacts with the at least one self-healing material to solidify and/or expand the at least one self-healing material to form a solidified section within the at least one chamber that seals the hole, and wherein the foreign fluid is one of ambient air and water.