Research of structure and properties of Cu-Pb-Cu composite interface, obtained by technology of pack rolling of the pair of mutually insoluble metals, was performed using the methods of metallography, micro-and nano-hardness, mechanical tests, energy-dispersion elementary analyses. The work was aimed at the analyses of possible mechanical mechanisms of mass-transfer, determining the hardness of metal joint in conditions of absence of inter-diffusion. It was shown that different intensity of mass transfer of copper and lead takes place through the composite interface, which corresponds to the results obtained on the other system of dissimilar materials-copper-niobium. Qualitative explanation of these patterns was offered on the basis of more intensive plastic flow of fusible compound of the composite in conditions of roll-bond joining.

The paper considers the neutron-producing tantalum-tungsten-tantalum target using a niobium interlayer manufacturing variant by means of vacuum hot roll bonding for the research nuclear facility «Source of Neutrons». The metallography results and the Ta-W-Ta solid-phase junction specimens mechanical testing ones obtained by hot roll bonding in vacuum, both immediately after production and after the heat treatment in the temperature range of 900…1300°C after roll bonding, are presented. The influence of thermal annealing on the interaction nature of the clad layers with each other and with the core tungsten material of the Ta-W-Ta solid-phase junctions with Nb interlayers obtained by vacuum hot roll bonding has been studied.

Nano-mechanisms of solid-phase bonding of tungsten and tantalum, which are implemented in the manufacture of a neutron source target for the research nuclear facility (RNF) of NSC KIPT, are considered. This facility is a new type of nuclear reactor, in the core of which the intensity of the nuclear fission reaction of the uranium isotope 235U is controlled by an electron accelerator. An installation for joining metals in the solid phase is described, its parameters are given, as well as the parameters of the joined metals. An electron-probe X-ray spectral analysis of the interface between the samples was carried out. The physical foundations of the nano-mechanism of bonding in the solid phase of tungsten and tantalum at the dynamic and isostatic stages at hot vacuum pressing are formulated. Experimental data on the relative temperature convergence of rolls at the dynamic and isostatic stages of hot vacuum pressing have been obtained.

The paper presents the quality studies results of the Ta-W-Ta solid phase junctions with Ti interlayers obtained by hot roll bonding in vacuum, that determine the work suitability in the form of neutron producing targets at the research nuclear facility ‘Source of Neutrons’. It is shown the layers mutual penetration level of the Ta-W-Ta solid-phase junction with Ti interlayers which provides a high level of clad layers adhesion when using the hot vacuum roll bonding method. The deformation parameters necessary both for the solid phase bond occurrence and for the reliable solid-phase junction formation of tantalum and tungsten refractory metals layers through a titanium interlayer, with a joint strength exceeding the value of a less durable material are determined. The possibility of chemical vapor deposition (CVD) method using for side faces coating of targets was studied.