Ch.G. Pak, V.M. Batrashov, S.V. Skiba, P.I. Serov Penza State University Welding engineering and materials technology department, Penza State University, 40, Krasnaya Str., , Penza tel., fax (8412) AN OPPORTUNITY TO PRODUCE COMPOSITION MATERIALS IN THE MODE OF SELF-PROPAGATING HIGH- TEMPERATURE SYNTHESIS AND SHOCK-WAVE LOADING

The objective of the work: Producing protective coatings using the method of gas-dynamic spraying, improving technological effectiveness of spraying and reducing the cost of materials for spraying

One of promising materials is TiB2, titanium boride. Ceramic solids based on it have high hardness and wear resistance. Their plastic properties are sufficient for producing protective coatings, but the main disadvantage of such coatings is abrasion wear. Abrasion wear is an inadmissible type of destruction as it is characterized by sharp deterioration of surface layers quality.

The TiB2 powder was pre-screened using the air separator to sort out fractions with the particle size being 1-6 microns. The nickel powder was screened using the sieves with the fraction size being microns, then Ni and TiB2 powders in the quantity of 40% and 60% respectively were being mixed in an eccentric mixer for 8 hours with the following powders mechanical activation in a ball mill. After the mechanical activation compacts with the size of 100x50 and the thickness of up to 10 mm were produced with the help of a hydraulic press. The compact produced was being sintered in the argon atmosphere at the temperature of 1,1300С for 3 hours, then the particles with the size of microns were ground in a ball mill and then they were used for spraying. The compact material ground in the ball mill was later used for plasma spraying of protective coatings. Spraying was performed with on-site protection with the nozzle using the universal plasma installation UPU-3D

The coating tribological properties analysis showed that under the conditions of dry gliding friction paired with steel 65G the developed coatings have low wear values (1.6-3 microns/km) with sufficiently low friction coefficients ( ). It was also stated that the more the testing velocity, the less the coating wear. Using the X-ray analysis methods the TiO2 and B2O3 interstitial oxides were found. These oxides are able to form solid solutions with each other, thus producing an amorphous film showing low tendency to adhesive interaction with steel and protecting the material from damage in the process of friction. So, the TiO2- B2O3 oxide film formation conditions high tribotechnical characteristics and indicates that the process of mechano-chemical wear is normal. RESULTS

The pattern of shock-wave loading 1 − electric detonator; 2 − explosive container; 3 − flying plate; 4 − tube; 5 − container; 6 - powder ; 7 − plate-base; 8 − woodchip board; 9 − soil.

Blasting in the open polygon conditions Explosive container before explosion

Explosive calculation To place the explosive carton containers were made. The quarry powder 6ZHV according to GOST was used as an explosive. The quarry powder 6ZHV is aimed at blasting in the open air. It contains trotyl as a sensitizer and ammonium nitrate – a matter with feebly marked explosive properties, decaying during detonation at the speed an order of magnitude less than powerful individual explosives. When 6ZHV explodes chemical reactions proceed in several stages.

Ст3+TiB 2 -Ni The protective coating sprayed on a steel plate

Microstructure TiB 2 specimen after mechanical activation in a ball mill TiB 2 + Ni specimen after shock-wave loading

Conclusions Producing ceramic solids for protective coatings spraying using the method of shock-wave loading is not only more profitable economically, but it also allows producing a coating with better physical-mechanical properties

Thank you for your attention! Welding engineering and materials technology department, Penza State University, 40, Krasnaya Str., , Penza tel., fax (8412)