Technical Papers
 
    Mechanical properties of an extruded pyramidal lattice truss sandwich structure
 
    The resistance of metallic plates to localized impulse
 
    The Effects of Topology Upon Fluid-flow and Heat Transfer Within Cellular Copper Structures
 
    Cellular Metal Truss Core Sandwich Structures
 
    Cellular Metals Manufacturing
 

 

Advantages


CMI extends advances made over the last 20 years in cellular materials through Microtruss™, its periodic cellular material. In comparison to monolithic metal forms, other periodic cellular materials like traditional honeycombs and metallic foams, the main advantages of this new class of material are that it is:

Multi-functional:
A Microtruss™ material is inherently capable of more than one function, including structural strength, blast protection, ballistic protection, and heat exchange. The results include a structurally strong, light-weight, heat exchanger or armor that provides both blast and ballistic protection. CMI is also investigating the co-optimization of such functions as shape morphing, catalytic support, and power storage.

Light-weight:
Microtruss™ structures have 2-3 times the compressive stiffness as solid material at the same weight. In applications in which weight is critical, a reduction in weight could be used to increase personnel protection levels, to carry larger payloads, or to allow for additional storage. Microtruss'™ weight savings also make it environmentally friendly by reducing fuel and energy expenditures, which enable greater speed.

Cost-effective:
CMI's manufacturing processes are designed around commercially available manufacturing routes and materials to provide the most cost effective product possible. Because Microtruss™ is both light-weight and multi-functional, it also offers greater value than its competitors.

Versatile:
The flexibility of Microtruss™ in terms of core topology, alloy, cell size, and relative density means that CMI's materials can be adapted to address a number of application variables.

Open-Celled:
Microtruss'™ periodic, open-celled topologies optimize heat transfer by enabling efficient fluid flow. They also facilitate the addition of materials needed for specific applications, such as magnets to provide a magnetic field or ceramics for increased ballistic resistance.

Environmentally Tough:
When titanium alloys or stainless steels are utilized, Microtruss™ can stand up to environmental challenges from the intense corrosion of marine applications to the high-heat conditions of space and re-entry vehicle applications.


Limitations of conventional materials include:

Monolithic Materials:

  • Heavy weight, high density
Microtruss™ is much lighter and less dense than monolithic forms, but it is also 3-4 times as strong in blast protection at the same weight.

Traditional Honeycombs:

  • Limited design options
  • Not multi-functional
  • Closed-cells
Through its diverse core topologies and ability to multi-function, Microtruss™ overcomes the limitations of traditional honeycombs and greatly expands their application possibilities. Because traditional honeycombs have closed-cells, they cannot be closely inspected, and they are not protected against fluid ingression, which can lead to de-bonding at structural joints. The open-cells of Microtruss™, however, enable close inspection and prevent fluid entrapment, creating a safer and more dependable product.

Metal foams:

  • Poor structural properties
  • Stochastic structure limits fluid flow in thermal management
Microtruss'™ structural properties are far superior to those of metal foams, which are often brittle. In terms of thermal management, metal foams are limited by their stochastic, or random (non-periodic), structure. Microtruss™ performs superior thermal management because of its periodic structure, which allows cooling fluids to flow through its core with less resistance and therefore less energy.