The researchers created a nanoscale mechanical metamaterial with extraordinary energy absorption
(Nanowerk News) A team of researchers from the Center for Materials Research of the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) and Chongqing University have succeeded in fabricating a mechanical metamaterial with very high energy absorption capacity using ion pathway technology. Their findings are published in Nature Communications as Editor Highlight (“Metamaterial made of free standing quasi-BCC nanolattices of gold and copper with ultra-high energy absorption capacity”).
Mechanical metamaterials are a class of composite materials that have an artificially designed structure, resulting in extraordinary mechanical properties that traditional materials lack. Among these materials, energy absorption mechanical metamaterials are able to absorb mechanical energy more efficiently, requiring the material itself to have high strength and high strain capacity. This is a challenging feat to achieve because they rarely coexist in general.
Nanolattice is a new class of mechanical metamaterials with characteristic sizes at the nanoscale. These porous materials have unique mechanical properties due to the effects of size, geometric configuration and material selection. Nanolattice is expected to bring revolutionary applications in the field of high-performance functional materials in the future, mainly due to its better mechanical properties and lighter weight.
Beam-structured nanolattices are the focus of research on nanolattice metamaterials. However, it is difficult to fabricate nanolattice blocks of metal with a beam diameter of less than 100 nm, making their mechanical properties ambiguous.
Using the Heavy Ion Research Facility in Lanzhou (HIRFL), the researchers were able to fabricate a new type of quasi-body-centered cubic (quasi-BCC) beam nanolattice metamaterial with ion pathway technology. The beam diameter of the quasi-BCC nanolattice can be as small as 34 nm, which is a record low beam diameter of a mechanical metamaterial.
The researchers demonstrated that gold and copper quasi-BCC beam nanolattices have excellent energy absorption capacity and compressive strength. In fact, the energy absorption capacity of the copper quasi-BCC beam nanolattice exceeds that of the previously reported beam nanolattices. The yield strength of the gold and copper quasi-BCC beam nanolattices exceeds that of the corresponding bulk materials by less than half the density of the latter.
Furthermore, the researchers revealed that the outstanding mechanical properties are mainly due to the synergistic effect of size effect, quasi-BCC geometry, and the good ductility of the metals.
Overall, this study sheds light on the mechanical properties of beam nanolattices and applies ion pathway technology as a new method for exploration of beam nanolattices with ultra-high energy absorption capacity.
