Gold in engineering and aerospace
Gold is extremely malleable and can be rolled or stretched to microscopic thickness. Techniques such as ‘vacuum deposition’, where gold is vaporised into a cloud and condensed onto a surface, make it possible to create thin films of gold for advanced engineering applications.
NASA’s James Webb Space Telescope, due to be launched in 2018, will search for the first galaxies that formed in the early universe. The telescope’s 18 hexagonal mirror segments have been covered with a microscopically-thin gold coating, making use of the metal’s properties as an efficient reflector of infrared light.
The same reflective properties have made gold a valuable coating for engineers in terrestrial settings. A thin coating of gold plating in windows reflects heat radiation, helping to keep buildings cool in summer and warm in winter, which lowers their energy costs and carbon emissions. In Toronto, Canada, all 14,000 windows on the Royal Bank Plaza are coated in 70kg of pure gold.
Engineers have also made use of gold’s conductive properties and its resistance to corrosion, incorporating it as a coating in fuel cells. These are typically made of bipolar plates made of a conductive material, such as stainless steel. Adding a thin layer of gold can extend the cell’s lifespan and reduce the resistance between elements of the cell, improving its efficiency.