RESEARCH OF THE KINETICS OF THE FIRST HYDRATION OF MATERIAL TIFE + TI2FE, OBTAINED BY EXPLOSIVE LOADING OF MIXTURES OF TITANIUM AND IRON POWDERS

The kinetics of the processes of primary hydrogenation of material based on TiFe obtained by explosive pressing of titanium and iron powders with subsequent heat treatment has been investigated. Using the results obtained and mathematical processing of the curves using the Avraami-Erofeev equation, it was revealed that the mechanism of their saturation with hydrogen corresponds to the classical concepts of reaction diffusion. The process begins with the formation of a layer of solid solutions of hydrogen on the surface of the material in the initial phases of the material and after the latent period continues with the formation of a layer of hydride phases. t is shown that the hydrogen storage material TiFe + TiFe has a significantly higher hydrogen capacity than single-phase TiFe.

STUDY OF THERMOMECHANICAL PROPERTIES OF UHMWPE

The paper presents comparative studies of the thermomechanical properties of ultra-high molecular weight polyethylene (UHMWPE) and its composite containing 0.5% coke-graphite powder (CGP). It was found that explosive pressing with a pressure of 0.25-0.6 GPa provides high heat resistance of UHMWPE and the investigated composite (154-156 ° C). The heat resistance of the composite decreases to 143-145 ° C, but it is higher than that of a similar material after static pressing (128 ° C).

RESEARCH OF THERMAL PROPERTIES OF UHMWPE BASED COMPOSITES AFTER EXPLOSIVE PRESSING

The thermal characteristics of the initial UHMWPE and its composites with QGP and MDF, as well as those obtained by explosive pressing (VP), have been investigated. It has been established that explosive pressing leads to hindering the processes of melting and thermal destruction, which may be associated with chemical interaction, the formation of inter- and intramolecular cross-links characteristic of this polymer. UHMWPE and its compositions with 3% CHP after VP have higher melting points of the crystalline phase, thermal oxidation and thermal destruction in comparison with the starting materials of similar composition. In the UHMWPE composition with 10% MDF, no increase in thermal properties after VP was observed, similar to the original fluoroplastic.

RESEARCH OF THERMAL PROPERTIES OF UHMWPE BASED COMPOSITES AFTER EXPLOSIVE PRESSING

The thermal characteristics of the initial UHMWPE and its composites with QGP and MDF, as well as those obtained by explosive pressing (VP), have been investigated. It has been established that explosive pressing leads to hindering the processes of melting and thermal destruction, which may be associated with chemical interaction, the formation of inter- and intramolecular cross-links characteristic of this polymer. UHMWPE and its compositions with 3% CHP after VP have higher melting points of the crystalline phase, thermal oxidation and thermal destruction in comparison with the starting materials of similar composition. In the UHMWPE composition with 10% MDF, no increase in thermal properties after VP was observed, similar to the original fluoroplastic.

RESEARCH OF THE MECHANISM OF COMPACTION OF MIXTURES OF POWDERS OF REFRACTORY CARBIDES WITH A METALLIC BOND IN EXPLOSIVE PRESSING ON A METAL SUBSTRATE

The results of investigations of the features of the behavior of the components of mixtures of refractory carbide powders with metals during explosive pressing are presented. It is shown that the main factor determining the compaction of mixtures is the dynamic flow of one of the phase components of the mixture into the initial pores of the powder. As the phase component of the mixture, the movement of which limits the degree of compaction and leads to the formation of a continuous matrix in the structure of the material pressed by the explosion, both the metal binder and the carbide component of the material can act.

RESEARCH OF THERMOMECHANICAL PROPERTIES OF UHMWPE AND ITS COMPOSITE WITH QGP AFTER EXPLOSIVE COMPRESSION

To develop the technology of explosive pressing of ultrahigh molecular weight polyethylene (UHMWPE) and its powder composite mixtures with inorganic fillers, the thermomechanical properties of an unfilled polymer and a composite containing 3% coke graphite powder (KGP) after explosive pressing were studied. It was found that explosive pressing with a pressure of 0.25-1.3 gpa provides high heat resistance of UHMWPE and the studied composite (154-156 °C), and the filler restrains the thermal deformation expansion of the polymer, which is associated with increased intermolecular and adhesive interaction at the phase boundary. Thus, the method of explosive pressing can be recommended for industrial processing of UHMWPE and its composite mixture with 3 % KGP.

Study of structure formation in aluminum filled polytetrafluoroethylene after explosive compression

The features of the structure formation in polytetrafluoroethylene filled with 10 and 30% (vol.) aluminum after static and explosive pressing have been studied. It was revealed that after static pressing during sintering, interphase separation occured, which is confirmed by the formation of structures of the «closed buds» type. After explosive pressing with sintering, fibrils between polytetrafluoroethylene and aluminum and a polymer layer covering metal particles were found, and there was no interfacial separation that indicates the formation of a strong adhesive bond and is confirmed by the formation of aluminum fluoride.

Thermal processes under explosive loading of amorphous alloy powders

The article deals with the state of production of bulk amorphous and nanocrystalline materials. Conditions for the preservation of the “X-ray” amorphous state in compact materials obtained by explosive pressing of amorphous alloy powders are formulated. The two-front Stefan problem is solved and it is shown that the cooling rate of liquid layers on the contact surfaces of powder particles under explosive loading corresponds to the critical quenching rate of the formation of amorphous structures in metal alloys.

OBTAINING COATINGS FROM HARD ALLOYS BY EXPLOSIVE LOADING OF MIXTURES OF CHROME CARBIDE AND TITANIUM CARBIDE POWDERS ON METAL BASES

The principal features of the mechanism of formation of coatings from hard alloys during their production by explosive pressing of mixtures of CrC and Ti powders on metal substrates are described. The phase composition and structure of coatings deposited using loading by a plane normally incident detonation wave and sliding loading are considered.