For space and not only. SSC "Keldysh Center" is completing research on self-healing materials

Employees of the "Keldysh Center" and their developments at MAKS-2021

One of the promising areas in the field of materials science is the creation of the so-called. self-healing materials. These are special composites capable of independently repairing damaged areas while maintaining the main mechanical characteristics. Self-healing composites are being developed abroad and in our country. The main domestic projects in this direction are being created at the State Scientific Center “Keldysh Center” from Roscosmos.

Promising direction

The Keldysh Center, together with the Russian Foundation for Basic Research and a number of other scientific organizations, has been working on the topic of self-healing materials over the past few years. The main ideas and concepts have already been found, as well as studies of specific compounds and composites based on them have been carried out. The successes achieved have been reported in peer-reviewed journals many times. In addition, samples of new materials are shown at exhibitions.

The current version of the promising composite was demonstrated at the past exhibitions MAKS-2021 and Army-2021. He has already passed laboratory tests, during which he confirmed the calculated ability to recover from punctures and cuts. On prototypes, damage up to several millimeters in size was quickly and efficiently "tightened".

According to the organization-developer, research work on the promising project will be completed in December this year. Further plans have not yet been disclosed. Perhaps, the "Keldysh Center" and other enterprises will start working out the issues of introducing the new composite into practice.

The self-healing composite currently on display is a soft multilayer material suitable for a variety of products. First of all, we are talking about inflatable elements for various purposes. These can be habitable compartments with an air atmosphere, tanks for liquids, etc.

New material

The promising composite is based on borosiloxane and its compounds. The compounds used in the composite have the properties of a non-Newtonian fluid, due to which the necessary functions are provided - the ability to withstand static loads and recover from damage.

Borosiloxane properties: a) - rebound due to elasticity under shock loading; b, c) - fluidity under the influence of gravity; d, e) - stretching of the substance

Borosiloxane can be used to create various composites that generally have a similar architecture. A three-layer system is proposed. External and internal can be made of different materials, giving the required mechanical characteristics. In particular, it can be cross-linked borosiloxane - a substance with the use of fibers of one type or another. Silicone and silicone-impregnated fiberglass were also tested.

Between the outer layers is placed a relatively thick matrix layer of viscous borosiloxane in pure form or with fiber filling. It is he who uses all the properties of a non-Newtonian fluid and is responsible for the so-called. mass transfer to the damaged area, leading to the "healing" of the hole. Depending on the composition of the composite, other layers may have similar properties. Moreover, all layers have their own functions, both mechanical and in the process of tightening damage.

The principle of the self-healing composite is quite simple. An inflatable or other product designed to work with an internal atmosphere with a certain pressure is made of such material. The latter creates tension at which the inner layer of the composite has the properties of an elastic substance. This behavior persists under impact or other load.

If one or more layers are damaged, the tension is reduced, as a result of which borosiloxane begins to exhibit the properties of a viscous liquid. It seeks to leak into the hole and, as a result, literally closes it up. Due to this, the release of the atmosphere from the product stops, and loads reappear, making the composite elastic and resistant to impact.

The rate of damage recovery depends on the architecture of the composite, on the composition of the borosiloxane matrix, on the nature of the hole, etc. Small dents and through damage are repaired in a few seconds. Larger breaks take up to several minutes. The maximum possible size of "healed" damage is determined by the thickness of the inner layer and, accordingly, the amount of mass available for transfer. However, so far we are talking only about millimeters.

For space and beyond

The Keldysh Center is the headquarters of Roscosmos in a number of regions. In particular, it is responsible for the development of the direction "Functional materials for space technology". This indicates that new self-healing materials are being created primarily for the rocket and space industry.

Scheme of work (left) and cross-section of the composite (right)

The proposed composites have several important features. In addition to their ability to recover, they are lightweight and flexible. All this allows them to be used as structural materials for some products and objects, giving a certain level of protection. In addition, they can be used together with other materials as additional protection against mechanical damage.

For example, a self-healing composite can be used to protect a spacecraft from debris or micrometeorites. Such material will absorb the impacts of small objects and extinguish their energy, preventing them from damaging the main components of the ship. In addition, the composite will be able to seal the holes, which will extend the life of the entire system.

Also, new composites can find application in next generation spacesuits. In this case, it is possible to create spacesuits both for work in orbit and for the lunar program. In both cases, the properties of the new materials will be beneficial and will improve the performance of the suits.

In the distant future, self-healing materials can be used in the construction of permanent structures, such as stations on the moon. A composite dome of the required dimensions will be lighter than any other structure, which will simplify its delivery and installation. Besides, with the help of borosiloxane, the problem of minor repairs and leaks due to "attacks" of micrometeorites will be solved.

Naturally, recoverable composites can be used not only in space, but also on Earth. They can be used to make containers for various purposes, it is possible to use them in the construction of equipment or structures, etc. In general, it all comes down to the necessity and feasibility of using such materials in specific projects.

Experiences and practice

However, while the promising project of the "Keldysh Center" and related organizations is only at the stage of research work. They will be completed at the end of the year, and then the main results and real prospects of the direction will be clear. Then it will be possible to work out the issues of introducing new materials into real projects.

In theory, self-healing materials can be used in a wide variety of fields and have a great future. However, until now, their introduction has been impossible due to the lack of well-developed and "technically mature" formulations and formulations. The solution to this problem is approaching the desired end - and soon the new technology will be in the hands of designers of rocket and space technology.

Comments

[Vladimir_2U]

and soon the new technology will be in the hands of designers of rocket and space technology.

If by that time we still have such constructors.

[Gunther]

a promising technology, reminded biotechnology of the Strugatsky (early).
the designers will remain, but the bad thing is that a young scientist is forced to publish his developments in the open access - a malicious "citation index", etc. , "partners" now do not even need reconnaissance.

[Vladimir_2U]

Quote: Gunter

harmful "citation index"

By the way, yes! But pseudo-scientific figures are so proud.

[Gunther]

WoS (the us library database) is occupied by mattresses, Yukey and Dutch - publications of Russian scientists either will not reach, or will be in cropped form.
in any case, the data (developments) are at the disposal of the "partners".
to ensure national security, it is necessary to create a national system of scientific citation indices, this is at least.

[Aviator_]

it is necessary to create a national system of scientific citation indices, this is at least.

It is, this is a good old list of VAK publications, especially since it is peer-reviewed, so it's hard to shove through bullshit. And let the Hirsch indices be measured against each other there.

[Gunther]

... And the Hirsch indices
let them face each other there.

the fact is that funding, after the "reform" of the Russian Academy of Sciences ("On assessing the performance of scientific organizations" post-government), depends on "scientific citation", citing in foreign journals will be bullshit (and the valuable will be reserved for internal use), and this bullshit will get funding.
in addition, scientists are beginning to depend not on recognition within Russia (RSCI), but on Google Scholar, WOK, SCOPUS and WOS.

[Aviator_]

Unfortunately, you are right. This is from the series "insanity grew stronger."

[Albert1988]

Quote: Gunter

the fact is that funding, after the "reform" of the Russian Academy of Sciences ("On assessing the performance of scientific organizations" post-government), depends on "scientific citation", citing in foreign journals will be bullshit (and the valuable will be reserved for internal use), and this bullshit will get funding.
in addition, scientists are beginning to depend not on recognition within Russia (RSCI), but on Google Scholar, WOK, SCOPUS and WOS.

Eh, well, you do not know how it works, so please do not write ... This applies only to science in the full sense of "civil", all developments of strategic importance no one in full will not publish anywhere at all and funding for them goes through completely different channels than the good old RFBR ...

Py.Sy .: And yes, no one will quote "bullshit" in foreign magazines, just the opposite. Because of this, some domestic "academicians" (like the ever-memorable father and son of the Atabekovs, who sell counterfeit vodka) were very worried that they would not receive funding from the state for free for their sawn "bullshit". And I repeat - this applies only to those areas where, by definition, there is nothing secret ...

[Albert1988]

Quote: Gunter

malicious "citation index" and the like. , "partners" now do not even need reconnaissance.

Do not worry - no one publishes secret developments, only those that are not of strategic importance ...

[Filxnumx]

I hope there will be even fewer of you. Zadolbali already "vserosralshchiki"

[Vladimir_2U]

Quote: Fil743

I hope there will be even fewer of you.

Touched by people who look at everything through a pink point, but at the same time vicious like ferrets.

[awdrgy]

Of course, less and this is quite logical. I remember the phrase of John Silver about the dead living and envy

[Serge-667]

In vain minus. In fact, it is absolutely true.

[Evil troll]

The asphalt would be nice self-tightening.

[Filxnumx]

it is necessary to steal less and observe the stacking technology. And you don't need to invent anything.

[dauria]

The asphalt would be nice self-tightening.

The tanks were protected during the Second World War. The rifle caliber was tightened. There would be rubber ...

[awdrgy]

Well, this is in the hyper distant perspective))

[Avior]

... However, until now, their introduction has been impossible due to the lack of well-developed and "technically mature" formulations and formulations. The solution to this problem is approximated

Automotive paints that heal scratches themselves have long been a reality.
Only the results of their application are controversial. Both in terms of time and price.

[out of habit]

Well, auto paint does not experience stress, but I wonder what is the force of this "self-tightening" if the "patient" is under pressure, for example, in space?

[Avior]

It's not just paints
There are also power applications.
It has been used in fuel tanks for a very long time.

On combat aircraft, the internal walls of fuel tanks are protected with foam, the pores of which are filled with a coagulator (from the Latin coagulatio - coagulation, thickening), which hardens upon contact with air when a hole occurs as a result of combat damage or a lightning strike. The coalescer, flowing from the pores of the foam into the hole, fills it, hardens and prevents fuel from escaping. The internal volumes of the tanks are filled with lightweight polyurethane porous plastic having a reticular (spongy, porous) structure, which ensures self-extinguishing of the combustion process, regardless of the cause of its occurrence. This significantly increases fire and explosion safety, increases the combat survivability of the aircraft, naturally, at a certain cost of the useful volume of fuel tanks and weight.

There are other uses as well, such as superelastic cameras for transportation.

Such cameras appeared on the market relatively recently, but captured some part of the market. The idea is that the camera material is highly elastic and soft. Small punctures heal. Trapped sharp objects remain inside the hole and prevent air from escaping like a plug. In addition, the chamber itself is much more elastic and therefore the puncture is more difficult to "catch". This thing is new and controversial, but it has some effectiveness.

Only this is a very expensive pleasure.
There are also compounds that are injected into the chamber to ensure similar properties - small punctures are tightened, if something large gets in and left, it self-seals and you can ride with a nail in the tire for a long time.
But all the same, their use is limited.

[Ross xnumx]

Due to the available developments and the research stage:

However, while the promising project of the "Keldysh Center" and related organizations is only at the stage of research work. They will be completed at the end of the year, and then the main results and real prospects of the direction will be clear.

It becomes clear that in the near future the obtained material can only serve the space industry ...

[Filxnumx]

The material is good, no doubt. But from feminine logic, armed with a drill, he won't save. We need to continue research. It's a pity that chemists will not be able to say their weighty word: materials that swell from contact with oxygen in the air are in themselves quite dangerous. But simple spongy rubber in contact with kerosene, I remember, reliably "healed" holes from a caliber of 12,7 mm.

[Undecim]

If one or more layers are damaged, the tension is reduced, as a result of which borosiloxane begins to exhibit the properties of a viscous liquid. It seeks to leak into the hole and, as a result, literally closes it up. Due to this, the release of the atmosphere from the product stops, and loads reappear, making the composite elastic and resistant to impact.

No matter how many website authors try to cover complex scientific and technical issues, the picture is depressing.
Borosiloxane exhibits the properties of a viscous liquid in the absence of external stress. And when one or more layers are damaged, borosiloxane exhibits the property of elasticity due to the intermolecular interactions of boron and oxygen atoms. Due to this characteristic, borosiloxane-based materials under low-speed loads as part of composite systems are able to carry out mass transfer to the damaged area and heal the defect.