Metal nano powder on the absorption of electromagnetic waves with special function. Iron, cobalt, zinc oxide powder and metal powder can be used as military use high-performance carbon package millimeter wave stealth material, visible light, infrared stealth material and structured stealth materials, and mobile phone radiation shielding material.
The different nanometer metal hardness change is due to different plastic deformation mechanism. Softa Luke Anthony team with French UNIROUEN and nanjing university of science and technology partners using atom probe technology and high resolution electron microscopy, found that the softening behavior of nanometer Ni - Mo sample preparation state is caused by deformation of grain boundary migration mechanism of a mechanical drive. And nano Ni - Mo samples occurred in the process of annealing the grain boundary relaxation and grain boundary segregation of solute atoms, can reduce the grain boundary, improve the stability of grain boundary, the boundary behavior under the action of external force, it is hard to start plastic deformation by expanding of dislocation nucleation and motion. Due to the dislocation nucleation is directly proportional to the inverse of the stress and the grain size, sample grain size decreases hardness is not ". Very small grain size of nanometer metal hardening and softening behavior to fully demonstrate the microscopic deformation mechanism controlled by the stability of the grain boundary. The findings for the design and preparation has excellent properties such as ultra-high hardness new nano metal material provides a new way of thinking.
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