Self Healing Metals and Alloys - Including Structural Alloys and Self-healing Solders

A self healing material in which carbon nanotubes are incorporated in the matrix of alloys, including aluminum, wherein the internal cavities of carbon nanotubes will be filled with a suitable low melting alloy, and then incorporated into the matrix of aluminum alloys to form the nanocomposite. The cracks will break the nanotubes, and at suitable temperatures, release the healing agent into cracks in the form of liquid;

• upon solidification of the liquid in the crack, with or without reaction with the matrix, the crack will be sealed.

A self-healing material in which a low melting alloy which does the healing can be present in the alloy matrix in the form of pockets without a container. Upon healing the pockets of low melting material melt and expand, and fill the crack and seal the crack upon solidification leading to self-healing. The low melting alloy of pockets can be eutectic pockets formed upon solidification.

A self healing alloy incorporating solid reinforcements including macro, micro and nano size shape memory alloys, particles and fibers. The shape memory alloys due to change in shape as a result of phase transformation compress the metal matrix and “shut” the crack thereby healing it. The solid reinforcements can be other materials which expand on phase transformation or reaction with the atmosphere in the crack to compress or fill the crack. The solid reinforcement, especially in nanostructured matrices, can promote healing of voids due to enhanced diffusion.

Use of electromagnetic induction, microwave, ultrasonic, ballistic, and laser energy to selectively locally heat and/or react the low melting healing alloys or shape memory alloy, or other reinforcements, to trigger self healing in a localized area.

A self healing composite against tribological lubricant failures incorporating hollow micro, macro or nanosize fibers or microballoons containing a lubricating fluid or low melting solid within hollow spaces. The temperature rise due to tribological lubricant failure will melt, expand the solid and liquid, and exude the liquid to the mating surfaces. The exuded liquid cools the rubbing interfaces and provides lubrication.