Cyclic Healing: Strengthening Metal at the Nanoscale

When designing a new material, engineers strive to make the material strong and defect-free. However, methods conventionally used to control the amount of defects in a material, such as applying heat or mechanical stress, can also have undesirable consequences in terms of the material's strength, structure, and performance. An international team of researchers from Carnegie Mellon University, Xi'an Jiaotong University in China, MIT, and Johns Hopkins University has developed a new technique called cyclic healing. Using their novel method, the researchers found that in nanoscale crystals, controlled, cyclic deformation tends to drive defects closer to the surface, eventually forcing them out of the material.