A unique structural material composed of cellular metals that can heal; a property useful for recovery of material and strength along the path(s) of stress in the structural member.
This healing cellular metal is a new structural material that can continuously self-repair cracks and redistribute cellular materials within itself at room temperature. This material is capable of reinforcing itself through the path of stress within the member while under standard conditions.
There is an increasing demand for greater reliability and longevity in load-bearing structures. Often failure of these structures could endanger lives and are increasingly too costly to repair. Additionally, additive manufacturing has enabled parts with complex shapes, but repairing these parts is very difficult using conventional technologies. There has always been a need and a vision of the future which includes structures with the ability to heal. Research efforts in healing materials have been largely based on polymeric and ceramic based composites with very little discussion of metallic-based healing materials.
This material is a new class of metallic structural members that:
- can be healed at room temperature in response to catastrophic failure;
- strengthen areas that experience loads near their yield to prevent future failure; or
- modulate the stiffness of structural member.
These capabilities can be built into a new or currently used structural member or developed as a repair process where they member is removed, healed, and reinstalled.
The healing and reinforcing properties are enabled by a cellular metal infiltrated with an electrolyte. Upon applying a voltage to the metal, additional metal is electroplated to heal or strengthen the desired area. The target area and healing capability can be controlled using a tunable insulating coating on the conductive metal. The cellular nature of the structural member is required and facilitates metal transport from other areas of the material to the area that needs reinforcement, thus, enabling a faster mass-transport process at room temperature.
The inventors used cellular metal for the study