This work is devoted to the study of the processes that take place in the welding gap during explosive welding (EW). In the welding gap, when plates collide, a shock-compressed gas (SCG) region is formed, which moves at supersonic speed and has a high temperature that can affect the quality of the weld joint. Therefore, this work focuses on a detailed study of the parameters of the SCG. A complex method of determining the SCG parameters included: determination of the detonation velocity using electrical contact probes, ceramic probes, and an oscilloscope; calculation of the SCG parameters; high-speed photography of the SCG region; measurement of the SCG temperature using optical pyrometry. As a result, it was found that the head front of the SCG region moved ahead of the collision point at a velocity of 3000 ± 100 m/s, while the collision point moved with a velocity of 2500 m/s. The calculation of the SCG temperature showed that the gas was heated up to 2832 K by the shock compression, while the measured temperature was in the range of 4100–4400 K. This is presumably due to the fact that small metal particles that broke off from the welded surfaces transferred their heat to the SCG region. Thus, the results of this study can be used to optimize the EW parameters and improve the weld joint quality.

In this study, SHS was used to produce metal-intermetallic-ceramic laminate AlMg6-NiAl-TiC composite. The experiment conducted without a cylindrical powder pellet holder produced no joint between the NiAl and AlMg6 sheet. On the other hand, the experiment conducted inside a cylindrical powder pellet holder (CPPH) with a blind hole produced a joint. It was found that the AlMg6 sheet had a temperature of 400–550 °C across its entire thickness during SHS. The study of the microstructure and energy-dispersive analysis (EDS) of AlMg6-NiAl-TiC composite showed that it had five layers: (1) ceramic layer of 7-mm-thick TiC; (2) the upper diffusion layer that formed at the interface between NiAl and TiC consisted of TiC + NiAl; (3) an intermetallic layer, which consisted of 13-mm-thick NiAl; (4) the lower diffusion layer, which formed at the interface between NiAl and AlMg6; and (5) a layer of 4-mm-thick aluminum alloy AlMg6. The EDS showed that during the synthesis of NiAl and its interaction with the surface of the AlMg6 sheet, mixing of the components of the initial materials (NiAl, AlMg6) in the joint interface occurs. At the interface of NiAl and AlMg6, the microhardness was 790–870 HV, which indicates the presence of quenching structures in the melted zones.

This paper presents the implementation of the first stage of a study on the synthesis of the intermetallic compound in the Ni-Al system under shock-wave extrusion (SWE). A method was developed and experiments involving SWE of the reactive Ni–Al powder mixture were carried out. As a result, it was possible to obtain up to 56 vol.% of the final product and achieve 100% synthesis of NiAl. The results of metallographic analysis indicate that the process of high-velocity collapse of the tube created conditions for the formation of a cumulative flow, which directly affects the phase formation in NiAl. It was shown that the presence of the central hole in the powder sample reduced the effect of the Mach stem on the homogeneity of the NiAl structure. It was also determined that with a central hole with a 5 mm diameter, the effect of the Mach stem could not be observed at all. The goals of further studies are achieving 90–100 vol.% of the final product and reducing the porosity in the final product. Preliminary experimental studies have shown great potential for SWE to produce composite metal–intermetallic materials.

Multilayer composite materials, consisting of layers of aluminum alloy and steel, are used in the manufacturing of large engineering structures, including in the shipbuilding and railcar industries. Due to the different properties of aluminum alloys and steels, it is difficult to achieve high-strength joints by conventional welding. Therefore, these joints are produced by explosive welding. In the present work, the structure of a multilayer material, AA1070-AlMg6-AA1070 (aluminum alloys)-VT1-0-08Cr18Ni10Ti (steel), was investigated after explosive welding and heat treatments were performed under different conditions. The microstructure of the AlMg6 layer at the AlMg6-AA1070 interface consists of shaped anisotropic grains extending along the weld interface. The AA1070 layer is enriched with magnesium due to its diffusive influx from AlMg6. In the AlMg6 and VT1-0 layers, adiabatic shear bands are found that start at the weld interface and propagate deep into the material. The optimal temperature for the heat treatment is 450–500 °C, as internal stresses are reduced at this temperature and the grain structure of the AlMg6 layer is not coarse. Tear strength testing revealed that the tear strength of the composite material after explosive welding was 130 ± 10 MPa, which exceeded the strength of the AA1070 alloy.

A functionally graded composite NiAl-AlMg6 was prepared using the pressure of gaseous reaction products (impurity gases) produced during the synthesis of reactive powders in a sealed reactor. It has been shown that this method can be used to prepare a NiAl/AlMg6 composite with both chaotically oriented pores in the NiAl layer and unidirectionally oriented pores (lotus-type pores). The pore shape in NiAl was found to be dependent on the pressure of the impurity gases and hydrogen present in the starting titanium powder. A mechanism for pore formation in NiAl and AlMg6 composite during SHS is proposed. Thus, functionally graded high-temperature composites can be produced by SHS in a sealed reactor using the chemical reaction energy and the pressure of impurity gases and hydrogen. Additionally, minimizing the influence of impurity gases on the contact zone increases the interface area between NiAl and AlMg6.

In the present work the conductivity of fullerene C₆₀ crystals has been measured under smooth shock wave quasi‐isentropic loading conditions up to 30 GPa at initial temperature T=293 K. Not monotone behavior of conductivity has been revealed under compression of crystal with pressure increasing: ‐at first conductivity grows by many orders then it falls very fast. Conductivity increasing is explained by decreasing of bandgap of C₆₀ under compression whereas conductivity decreasing can be explained on the assumption that the energy barrier of polymerization of C₆₀ reduces with pressure increasing approximately in the same measure, as band‐gap energy.