Self-healing materials find their inspiration in nature’s biological organisms with self-repairing capabilities. Not without its challenges is the exploration into engineering self-healing properties for metals. The degree of difficulty is mostly due to the high temperatures needed and the chemistries involved in the process. But it’s happening and it’s an advantageous advancement on many levels.
Built-in Self-Healing for Metals
For any material thing to qualify for an autonomous self-healing status, the repair process has to happen without human intervention, hence the ‘smart metal’ category takes its place on the cutting edge of the technology runway.
The idea is to overcome the natural order of things to decay, and without human diagnosis, have an innate repair ability built-in to various materials, including metal. Environmental conditions, corrosion, and fatigue plague metal in particular. Microscopic cracks develop that are invisible to the human eye develop and compromise thermal integrity and life span.
Self-healing Halts the Creep Fractures in Metal
Self-healing metals circumvent the need for replacing and repairing, hugely extending the life of metals processed with self-healing capability that can respond to micro-damage. Early efforts to heal creep damage in steel relied on dynamic elemental precipitation. Now, a plethora of methodologies has been developed to assess self-healing capabilities in metal particularly.
Premature, low-ductility creep fracturing is the official terminology given to what happens to deteriorating metals. To render metals self-repairing is more difficult to achieve than it is in other materials. Precipitates, conducive to repairing and healing the defect sites are needed to nuke and neutralize the tendency to cavities and creep fractures.
Gold – a Secret Self-healer for Metal
For self-healing properties, what is looked for are precipitations that form in the matrix simultaneously at the defect site. Gold atoms were found to be successful as highly effective healing agents for certain alloys, resulting in adequate pore filling.
The benefits of self-healing metals stretch into many areas of saving such as cost of material failure, extended material lifetime, and reducing inefficiencies brought on over time. As with so many technologies, self-healing capability in metals is an exciting and ongoing field of development.