A student of Novosibirsk State Technical University (NETI) is testing a method for increasing the microhardness of metals. The essence of the method is the formation of a metal-based composite material through reinforcement using a laser growth method similar to printing on a 3D printer. The micro-hardness of reinforced titanium is doubled due to this technology.
The technique can be used to increase productivity in mechanical engineering and the aerospace industry.
The project "Laser additive incubation of titanium matrix composites" took first place in the competition of research papers of the IX International Scientific and Practical Conference "Chaplygin Readings". The scientific director of the project is Alexander Golyshev, Candidate of Physical and Mathematical Sciences, Senior Researcher at the Institute of Theoretical and Applied Mechanics SB RAS named after S.A. Khristianovich.
The technology developed by the student of NSTU-NETI allows replacing the traditional method of creating composite material with a new one — faster and more economical. The purpose of the method is to create a composite by direct laser incubation of a titanium matrix material while maintaining its mass and size, but with an increase in mechanical properties such as hardness, impact resistance, and corrosion susceptibility.
"One of the methods of increasing the strength of titanium alloys is reinforcement. For this, we use the laser build–up method, which allows us to weld the material in layers, which is similar to printing on a 3D printer. Boron particles are used for surfacing: the choice of this material is due to its lightness and strength. In Russia, this method is one of the most effective and affordable relative to similar technologies," commented Konstantin Kobylkin, the author of the project, a 4th—year student of the Faculty of Aircraft at NSTU-NETI.
To create composites, a direct laser growth unit is used, representing a laser mounted on a mechanical arm. The laser forms a "bath" of melt in the metal, into which a jet of powder mixture is fed. During the movement of the laser beam, the "bath" solidifies, forming a deposition on the titanium matrix material.
According to the student, this method can be applied to any metal, experiments have already been conducted on titanium and several composite fillers.
"To check the impact resistance, the samples are tested: the striker accelerates to a speed of 1200 km/h and hits the sample. The microhardness of a pure titanium sample without reinforcement is about 300-400 HV on the Vickers scale. According to our method, the microhardness of boron-reinforced samples reaches about 600 HV. Thus, the hardness of reinforced samples is twice as high as that of pure titanium," Konstantin said about the tests.
Currently, experiments are continuing at ITPM SB RAS, researchers are studying the possibility of reinforcing new metals. The head of the laboratory "Laser Technologies" ITPM SB RAS, Doctor of Technical Sciences Alexander Malikov, directs the research.