Metallic microlattices and applications

Lattice materials with dimensions close to micrometer scale are called microlattices. 

They can be produced from different materials [1] such as composites, polymers and metals.  

Here we focus solely on metallic microlattices and their manufacture, mechanical properties and possible applications.

[4]

Microlattices are periodic open cell structure, where the lattice formation occurs due to interconnected struts.
​

The study of metallic microlattices is still at a very early stage, and much is ongoing to uncover its full potential for structural applications.

Study [2] suggest that highly ordered lattices are stronger than disordered types of cellular materials, but they are extremely sensitive to strain localization. In addition, they could accumulate high amounts of localized damage in certain strut orientation.

Researchers [3] also reported that randomization in cell structures enhance the mechanical properties of the structures by eliminating the natural fault planes that commonly occur in ordered structures.

​Manufacturing of Lattices

[4]

Mechanical properties of metallic lattices vary with:

• composition of the material used;
• cell topology, periodicity, etc...;
• manufacturing method.

Applications of metallic microlattices

Typical applications of metal lattices are:

• lightweight structural concepts that can absorb acoustic, shock and vibration energy

• sandwich construction of aircraft fuselages and wing structures (efficient function/weight-efficiency ratio [5]). In general, sandwich core topologies are exhibiting stretching and compression qualities without bending [6].

•  protection system for flight recorders: a microlattice layer protects the memory device against crash [7]

•  Impact and blast resistant structures

• biocompatible porous structures

References:
​[1] J. Xiong, R. Mines, R. Ghosh, A. Vaziri, L. Ma, A. Ohrndorf, et al., Advanced microlattice materials, Adv. Eng. Mater. 17 (2015) 1253–1264. doi:10.1002/adem.201400471.
[2] M.H. Luxner, A. Woesz, J. Stampfl, P. Fratzl, H.E. Pettermann, A finite element study on the effects of disorder in cellular structures, Acta Biomater. 5 (2009) 381–390. doi:10.1016/j.actbio.2008.07.025.
[3] L. Mullen, R.C. Stamp, W.K. Brooks, E. Jones, C.J. Sutcliffe, Selective laser melting: a regular unit cell approach for the manufacture of porous, titanium, bone in-growth constructs, suitable for orthopedic applications, J. Biomed. Mater. Res. B Appl. Biomater. 89B (2009) 325–334. doi:10.1002/jbm.b.31219.
[4] M.G. Rashed, Mahmud Ashraf, R.A.W. Mines, Paul J. Hazell, Metallic microlattice materials: A current state of the art on manufacturing, mechanical properties and applications, (2016), doi: 10.1016/j.matdes.2016.01.146
[5] Y. Shen, High performance sandwich structures based on novel metal cores, PhD thesis, University of Liverpool, 2009
[6] V.S. Deshpande, M.F. Ashby, N.A. Fleck, Foam topology: bending versus stretching dominated architectures, Acta Mater. 49 (2001) 1035–1040. doi:10.1016/S1359-6454(00)00379-7.
[7] D.L. Miller, G. Kersten, W.A. Frost, Systems and methods for protecting a flight recorder, US8723057 B2, 2014. http://www.google.com/patents/US8723057 (accessed May 2016).