For 6,000 years, humans have been making things from metal because it’s strong and tough; a lot of energy is required to damage it. The flip side of this property is that a lot of energy is required to repair that damage. Typically, the repair process involves melting the metal with welding torches that can reach 6,300 °F.
Click here for original story, Engineers develop bone-like metal foam that can be ‘healed’ at room temperature
Source: Phys.org