7. June 2023
CEITEC BUT scientists Martin Kachlík and Jakub Roleček have been working on the development of ceramic armor for almost ten years. They arrived at a solution in the form of a solid connection of non-porous ceramics and aluminum alloys, which has no competition in the world. The resulting composite stands out for its fire resistance, high mechanical resistance and unlimited service life. It is a ballistic-resistant material that can protect military vehicles or police officers behind mobile shields from firearms or explosives. Scientists have found a new opportunity for it in the field of safe construction. In 2021, they moved part of the research under the banner of a university spin-off, now a start-up, TriCera.
A number of armor manufacturers rely on combining ceramics with a polymer matrix or offer steel armor. Due to its low weight, the variant with polymer is the most common type of armor. However, it has a low temperature and mechanical resistance and does not excel in longevity. Steel armouring, on the other hand, is very heavy and makes the mobility of people and vehicles difficult. "We followed the path between two existing solutions. We wanted to combine ceramics with something that would have a longer life and, above all, temperature resistance. So we essentially replaced the polymer adhesive with an aluminum alloy in the ballistic-resistant composite," Kachlík describes the initial experiments. However, the molten metal does not wet the ceramic and thus does not form a solid connection with it. It behaves similarly to mercury from a broken thermometer, which disintegrates into discontinuous balls on a flat floor. Tested armors made of this material looked fine at first glance, but due to the incoherence of the ceramic bodies with the matrix, they ceased to be effective after the first shot.
Even the surface treatment of the ceramics helped, which guaranteed a durable connection of the metal matrix with the ceramics even after several hits by penetrating projectiles. This resulted in a synergistic ceramic-metal armor, which, thanks to the combination of lower weight, mechanical and temperature resistance, found application not only in the protection of armored vehicles.
Martin Kachlík and his colleagues are currently working on the "Advanced Ballistic Shields for Personal Protection" project, on which they are collaborating with the Police of the Czech Republic. The goal is a mobile ballistic shield for special forces that would also have high resistance. It should also withstand situations where the currently used ceramic-polymer shields are discarded: "When a police officer needs to throw the shield down the stairs or use it as a ladder for tactical reasons, the manufacturers can no longer guarantee its ballistic resistance," explains Kachlík. With a new and more durable model with ceramic-metal armor, the police could use the shield repeatedly for a wider range of threats.
Two years ago, the researchers founded the spin-off TriCera, which began to participate in research activities that could not be carried out within the university or only with great difficulty. The spin-off was supposed to help put developed technologies into practice as quickly as possible. Initially, it seemed that the greatest interest would be in military applications of the new materials. But the situation changed with the war in Ukraine.
Martin Kachlík explains the reasons: "The European military industry focused mainly on quality and development, but not on production capacity. No one expected that a conflict could arise in Europe where so much military equipment would be destroyed on a daily basis. For many years to come, companies will focus mainly on replenishing warehouses, and development will probably be delayed."
Another problem is related to the above. If military development is slowing down, then it is very difficult for a small company like TriCera to offer partial innovations for an already existing solution: “The development of a combat vehicle requires cooperation from the very beginning. Manufacturers have to go through very demanding testing not only for ballistic resistance, and if they change just one screw, they basically have to go through it all over again. The use of new material for an already existing solution is therefore quite disadvantageous for manufacturers of combat vehicles."
Therefore, researchers began to focus on the civil sector, where there is still capacity for innovation. Not only is the project of mobile ballistic shields for the police promising, but there is also a chance to apply a ceramic-metal composite for a new generation of safes. High mechanical and temperature resistance is also important for this area, as well as weight reduction compared to competing safe solutions made of steel and concrete. "If we reduce the weight of the safe, while maintaining a high degree of protection, then we practically have no competition. Such safes could be used even where this was not possible until now, for example due to the load-bearing capacity of the floors and the like. Preliminary tests already show us that this is a very promising path," explains Kachlík.
Scientists from CEITEC BUT are among the world leaders in the field of ceramic-metal armor. No one else produces their certified solution. However, it needs to be promoted more intensively, especially within B2B (business to business) communication. Participating in trade fairs such as the Brno International Defense and Security Technology Fair – IDET should also help with this. Here, TriCera presented both armor for armored vehicles or police shields, as well as a demonstration of a possible solution for safes.
The results achieved by Martin Kachlík and Jakub Roleček are proof of the high level of materials engineering, but also of the diversity of research at the BUT. “I try to find the best solution for the application. It's partly physics, partly chemistry, and although many people don't think so, it's also largely design and manufacturing technology. What leads to success is a diverse team, where you can approach problems from different angles and say, for example, an idea is good in three ways but needs to be redesigned for the fourth,” concludes Martin Kachlík, giving an insight into the workings of the research team.