- #1
!Jon Snow!
- 35
- 0
they are permanently stuck?
Nugatory said:Yes, if the vacuum is hard enough and the surfaces are clean and smooth enough and we bring them together in the right way. Google for "cold welding"
Unlike cold welding process at macro-scale which normally requires large applied pressures, scientists discovered that single-crystalline ultrathin gold nanowires (diameters less than 10 nm) can be cold-welded together within seconds by mechanical contact alone, and under remarkably low applied pressures.[2] High-resolution transmission electron microscopy and in-situ measurements reveal that the welds are nearly perfect, with the same crystal orientation, strength and electrical conductivity as the rest of the nanowire. The high quality of the welds is attributed to the nanoscale sample dimensions, oriented-attachment mechanisms and mechanically assisted fast surface diffusion. Nanoscale welds were also demonstrated between gold and silver, and silver and silver, indicating that the phenomenon may be generally applicable and therefore offer an atomistic view of the initial stages of macroscopic cold welding for either bulk metals or metallic thin film.[2]
Yes, this is true. In the vacuum of space, there is no air or other substances to prevent the metal atoms from bonding together when they come into contact.
No, the bonding will not be permanent. The metal pieces may stay bonded together for a period of time, but they can eventually break apart due to external forces or temperature changes.
The bonding is caused by a process called cold welding, where the atoms of the two metal surfaces come into close contact and form strong bonds without the need for heat or pressure.
Yes, most metals are capable of cold welding in space. However, some metals, such as aluminum, form a thin oxide layer on their surface which can prevent bonding unless the layer is removed.
Cold welding can occur on Earth, but it is much less common due to the presence of oxygen and other substances in the atmosphere that prevent the metal atoms from coming into close contact. It is mainly observed in high vacuum environments or in certain industrial processes.