In this study the wear resistance, corrosion resistance, and oxidation resistance of boronized metallic alloys were investigated. Thermochemical treatment was performed by powder pack boronizing process at temperature 850-950°C for 4 h. Saw-tooth morphology and smooth interface microstructures were observed with an optical microscope; microhardness was measured across the coating depth. The phases present in the boron coatings depend on the substrate material. High-temperature oxidation resistance was investigated and it was found that boron coating on ferrous alloys can resist temperatures up to 800°C. The corrosion resistance of the boronized samples was improved and the corrosion rate was calculated for boronized and plain specimens. Wear testing was conducted by following the procedures of ASTM G99, ASTM D2526, and ASTM D4060. The obtained experimental results revealed that boronizing significantly improves the wear-resistance, corrosion-resistance, and oxidation resistance of metallic alloys.

Feasibility to use the high-speed liquid impact for joining similar and dissimilar metals was investigated experimentally. An experimental setup that entails a launcher for projectiles formation and samples folders was constructed. The experiments involved joining of sandwiches containing two or three layers of metals were impacted by a high-speed projectile. The metals combinations included copper, brass, steel, and nickel alloys. The generated samples were examined visually, the strength of the joint was explored, and the integrity of the weld was estimated using ultrasound. In most of the experiments metallurgical bonding of joined metals was confirmed. The results of the ultrasound test demonstrated high quality of the generated joints. The performed experiments showed feasibility of the liquid impact-based welding. This process is the improvement of the explosion welding. Unlike the explosion welding impact-based process does not require special placing of work pieces while the stresses in the impact zone can be precisely directed and controlled.

The objective of this study was to investigate material deformation in the course of a high-speed (>1500 m/s) water impact and to use the acquired knowledge for improvement of the forming technology. An experimental setup for projectile fabrication was constructed and a series of experiments involving sub-millimeter and micron scale metal deformation was performed. The geometry and topography of the generated samples were investigated using advanced surface examination techniques and the feasibility of the liquid impact based micro-forming technology was demonstrated.

It was shown that the liquid impact at the projectile speed of 1500 m/s affects a target similarly to an explosive deposited on the workpiece surface. A setup to investigate material deformation using the liquid impact was designed and constructed. The setup entailed a launcher for the acceleration of projectiles, a female die, a device for measuring the projectile momentum at the impact zone and a fixture for fastening the launcher and the die. The experiments included punching, stamping, extrusion, and forging, Special attention has been paid to the study of the microscale forging and extrusion. Forming of steel, spring steel, brass, aluminum, and copper samples was investigated. Dimensional stability and surface topography of the samples generated in the course of performed experiments were examined. The feasibility and effectiveness of the application of liquid impact for metal forming were shown.

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